Update client dependencies to enable build

Because "eslintConfig": { "extends": [ "react-app" ] } in package.json
would result in the following error during build:
"Failed to load config "react-app" to extend from.",
eslint-config-react-app was added as an explicit devDependency.

Because adding eslint-config-react-app as a devDependency led to
react plugin having a conflict in eslint-config-react-app packages,
the following was added to .yarnrc.yml
packageExtensions:
  react-scripts@*:
    peerDependencies:
      eslint-config-react-app: "*"

See the following for explanation of above two:
facebook/create-react-app#10463 (comment)

Becase @testing-library/jest-dom's types were recognized by
build command, @types/testing-library__jest-dom was added as
a devDependency.

.yarnrc.yml

@@ -9,3 +9,8 @@ plugins:
     spec: "@yarnpkg/plugin-workspace-tools"
 
 yarnPath: .yarn/releases/yarn-3.2.0.cjs
+
+packageExtensions:
+  react-scripts@*:
+    peerDependencies:
+      eslint-config-react-app: "*"

client/package.json

@@ -48,7 +48,9 @@
   },
   "proxy": "http://localhost:5000",
   "devDependencies": {
+    "@types/testing-library__jest-dom": "^5.14.3",
     "eslint-config-prettier": "^8.5.0",
+    "eslint-config-react-app": "^7.0.1",
     "prettier": "2.6.2",
     "rimraf": "^3.0.2"
   }

yarn.lock

@@ -3960,6 +3960,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/testing-library__jest-dom@npm:^5.14.3":
+  version: 5.14.3
+  resolution: "@types/testing-library__jest-dom@npm:5.14.3"
+  dependencies:
+    "@types/jest": "*"
+  checksum: 203443d0e7e5929fbc9e441146f92d85efa033b4697e427ed0164df1c40b720b6bb9bbd96a3171ea5fd8d9301b538fd0f49d4f35594d142afd0f6d2ecac25785
+  languageName: node
+  linkType: hard
+
 "@types/testing-library__jest-dom@npm:^5.9.1":
   version: 5.9.5
   resolution: "@types/testing-library__jest-dom@npm:5.9.5"
@@ -14158,8 +14167,10 @@ __metadata:
     "@types/react": ^17.0.20
     "@types/react-dom": ^17.0.9
     "@types/react-router-dom": ^5.1.7
+    "@types/testing-library__jest-dom": ^5.14.3
     axios: ^0.26.1
     eslint-config-prettier: ^8.5.0
+    eslint-config-react-app: ^7.0.1
     prettier: 2.6.2
     react: ^17.0.2
     react-dom: ^17.0.2