XXX rn-0.60: unlink all third-party libraries [phase 1]

React Native 0.60 uses radically different methods to find, include,
and link third-party libraries.

In most cases, a third party library will not need *any* explicit
linkage instructions, either on iOS or Android. (The days of fiddling
with our `.xcodeproj` are almost entirely gone, rather than merely
being replaced with fiddling with our Podfile.)

This is the first, automated step of the removal phase, done largely
with a nonce script (see below). There are two issues with this:

* The script removes certain customized Sentry build items which we'd
  prefer to keep. So we do. (These are simply excluded from the
  commit.)

* A few stray references are not removed from the Xcode project. These
  will be handled in phase 2.

The script follows.

```bash
(
  PACKAGES=(
    @react-native-community/async-storage
    @react-native-community/netinfo
    @remobile/react-native-toast
    @sentry/react-native
    react-native-device-info
    react-native-document-picker
    react-native-image-picker
    react-native-notifications
    react-native-orientation
    react-native-photo-view
    react-native-sound
    react-native-safari-view
    react-native-safe-area
    react-native-text-input-reset
    react-native-vector-icons
    react-native-webview
    rn-fetch-blob
  )

  for package in "${PACKAGES[@]}"; do
    echo -e "\033[34mUnlinking\033[0m \033[1m$package\033[0m..."
    react-native unlink "$package"
  done
)
```

android/app/build.gradle

@@ -191,20 +191,6 @@ repositories {
 }
 
 dependencies {
-    implementation project(':@react-native-community_async-storage')
-    implementation project(':@sentry_react-native')
-    implementation project(':@react-native-community_netinfo')
-    implementation project(':react-native-document-picker')
-    implementation project(':react-native-webview')
-    implementation project(':react-native-text-input-reset')
-    implementation project(':react-native-image-picker')
-    implementation project(':react-native-orientation')
-    implementation project(':@remobile_react-native-toast')
-    implementation project(':react-native-photo-view')
-    implementation project(':rn-fetch-blob')
-    implementation project(':react-native-sound')
-    implementation project(':react-native-device-info')
-    implementation project(':react-native-vector-icons')
     implementation fileTree(dir: "libs", include: ["*.jar"])
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation "com.android.support:appcompat-v7:${rootProject.ext.supportLibVersion}"

android/app/src/main/java/com/zulipmobile/MainApplication.java

@@ -2,24 +2,11 @@
 
 import android.app.Application;
 
-import com.RNFetchBlob.RNFetchBlobPackage;
 import com.facebook.react.ReactApplication;
-import com.reactnativecommunity.asyncstorage.AsyncStoragePackage;
-import com.reactnativecommunity.netinfo.NetInfoPackage;
-import io.github.elyx0.reactnativedocumentpicker.DocumentPickerPackage;
 import com.facebook.react.ReactNativeHost;
 import com.facebook.react.ReactPackage;
 import com.facebook.react.shell.MainReactPackage;
 import com.facebook.soloader.SoLoader;
-import com.github.yamill.orientation.OrientationPackage;
-import com.imagepicker.ImagePickerPackage;
-import com.learnium.RNDeviceInfo.RNDeviceInfo;
-import com.nikolaiwarner.RNTextInputReset.RNTextInputResetPackage;
-import com.reactnative.photoview.PhotoViewPackage;
-import com.reactnativecommunity.webview.RNCWebViewPackage;
-import com.remobile.toast.RCTToastPackage;
-import com.zmxv.RNSound.RNSoundPackage;
-import io.sentry.RNSentryPackage;
 
 import java.util.Arrays;
 import java.util.List;
@@ -42,19 +29,6 @@ public boolean getUseDeveloperSupport() {
     protected List<ReactPackage> getPackages() {
       return Arrays.asList(
           new MainReactPackage(),
-            new AsyncStoragePackage(),
-            new NetInfoPackage(),
-            new DocumentPickerPackage(),
-            new RNCWebViewPackage(),
-            new RNTextInputResetPackage(),
-            new ImagePickerPackage(),
-            new OrientationPackage(),
-            new RNSentryPackage(),
-            new PhotoViewPackage(),
-            new RCTToastPackage(),
-            new RNFetchBlobPackage(),
-            new RNSoundPackage(),
-            new RNDeviceInfo(),
             new ZulipNativePackage(),
             new NotificationsPackage()
       );

android/settings.gradle

@@ -1,31 +1,3 @@
 rootProject.name = 'ZulipMobile'
-include ':@react-native-community_async-storage'
-project(':@react-native-community_async-storage').projectDir = new File(rootProject.projectDir, '../node_modules/@react-native-community/async-storage/android')
-include ':@sentry_react-native'
-project(':@sentry_react-native').projectDir = new File(rootProject.projectDir, '../node_modules/@sentry/react-native/android')
-include ':@react-native-community_netinfo'
-project(':@react-native-community_netinfo').projectDir = new File(rootProject.projectDir, '../node_modules/@react-native-community/netinfo/android')
-include ':react-native-document-picker'
-project(':react-native-document-picker').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-document-picker/android')
-include ':react-native-webview'
-project(':react-native-webview').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-webview/android')
-include ':react-native-text-input-reset'
-project(':react-native-text-input-reset').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-text-input-reset/android')
-include ':react-native-image-picker'
-project(':react-native-image-picker').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-image-picker/android')
-include ':react-native-orientation'
-project(':react-native-orientation').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-orientation/android')
-include ':@remobile_react-native-toast'
-project(':@remobile_react-native-toast').projectDir = new File(rootProject.projectDir, '../node_modules/@remobile/react-native-toast/android')
-include ':react-native-photo-view'
-project(':react-native-photo-view').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-photo-view/android')
-include ':rn-fetch-blob'
-project(':rn-fetch-blob').projectDir = new File(rootProject.projectDir, '../node_modules/rn-fetch-blob/android')
-include ':react-native-sound'
-project(':react-native-sound').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-sound/android')
-include ':react-native-device-info'
-project(':react-native-device-info').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-device-info/android')
 
 include ':app'
-include ':react-native-vector-icons'
-project(':react-native-vector-icons').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-vector-icons/android')