Add Usage to QueryResponseWithUnsignedIndices (#74)

## Problem
`Usage` is now returned for data plane operations against serverless
indexes. This was included in the codebase in this PR where we replaced
the `vector_service.proto` file with generated classes that included the
most recent changes to the data plane including read units:
#66

However, the newer `QueryResponseWithUnsignedIndices` class does not map
`usage` so it gets dropped for query requests using this class.

## Solution
Update `QueryResponseWithUnsignedIndices` to handle `usage`.
I also added `toString()` overrides to all of the classes in
`unsigned_indices_model` since debugging/logging was difficult without
it.

## Type of Change
- [ ] Bug fix (non-breaking change which fixes an issue)
- [X] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] This change requires a documentation update
- [ ] Infrastructure change (CI configs, etc)
- [ ] Non-code change (docs, etc)
- [ ] None of the above: (explain here)

## Test Plan
Integration tests for this are pending, I believe @rohanshah18 has
integration test changes in flight so I didn't make any changes there.
We should add assertions on `queryResponse.getUsage().getReadUnits()`.

I've run data plane operations locally using the examples folder to
validate that we're seeing usage and read units on data plane responses.

src/main/java/io/pinecone/unsigned_indices_model/QueryResponseWithUnsignedIndices.java

@@ -2,6 +2,7 @@
 
 import io.pinecone.proto.QueryResponse;
 import io.pinecone.proto.ScoredVector;
+import io.pinecone.proto.Usage;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -11,14 +12,18 @@ public class QueryResponseWithUnsignedIndices {
 
     private List<ScoredVectorWithUnsignedIndices> matches;
     private String namespace;
+    private Usage usage;
+
 
     public QueryResponseWithUnsignedIndices(QueryResponse queryResponse) {
         if (queryResponse == null) {
             this.matches = Collections.emptyList();
             this.namespace = "";
+            this.usage = null;
         } else {
             this.matches = convertToScoredVectorWithUnsignedIndices(queryResponse.getMatchesList());
             this.namespace = queryResponse.getNamespace();
+            this.usage = queryResponse.getUsage();
         }
     }
 
@@ -52,4 +57,30 @@ public String getNamespace() {
     public void setNamespace(String namespace) {
         this.namespace = namespace;
     }
+
+    public Usage getUsage() { return usage; }
+
+    public void setUsage(Usage usage) { this.usage = usage; }
+
+    /**
+     * Convert the given object to string with each line indented by 4 spaces
+     * (except the first line).
+     */
+    private String toIndentedString(Object o) {
+        if (o == null) {
+            return "null";
+        }
+        return o.toString().replace("\n", "\n    ");
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder sb = new StringBuilder();
+        sb.append("class QueryResponseWithUnsignedIndices {").append("\n");
+        sb.append("    matches: ").append(toIndentedString(matches)).append("\n");
+        sb.append("    namespace: ").append(toIndentedString(namespace)).append("\n");
+        sb.append("    usage: ").append(usage).append("\n");
+        sb.append("}");
+        return sb.toString();
+    }
 }

src/main/java/io/pinecone/unsigned_indices_model/ScoredVectorWithUnsignedIndices.java

@@ -69,4 +69,28 @@ public SparseValuesWithUnsignedIndices getSparseValuesWithUnsignedIndices() {
     public void setSparseValuesWithUnsignedIndices(SparseValuesWithUnsignedIndices sparseValuesWithUnsignedIndices) {
         this.sparseValuesWithUnsignedIndices = sparseValuesWithUnsignedIndices;
     }
+
+    /**
+     * Convert the given object to string with each line indented by 4 spaces
+     * (except the first line).
+     */
+    private String toIndentedString(Object o) {
+        if (o == null) {
+            return "null";
+        }
+        return o.toString().replace("\n", "\n    ");
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder sb = new StringBuilder();
+        sb.append("ScoredVectorWithUnsignedIndices {").append("\n");
+        sb.append("    score: ").append(toIndentedString(score)).append("\n");
+        sb.append("    id: ").append(toIndentedString(id)).append("\n");
+        sb.append("    values: ").append(toIndentedString(values)).append("\n");
+        sb.append("    metadata: ").append(toIndentedString(metadata)).append("\n");
+        sb.append("    sparseValuesWithUnsignedIndices: ").append(toIndentedString(sparseValuesWithUnsignedIndices)).append("\n");
+        sb.append("}");
+        return sb.toString();
+    }
 }

src/main/java/io/pinecone/unsigned_indices_model/SparseValuesWithUnsignedIndices.java

@@ -42,4 +42,25 @@ public List<Float> getValuesList() {
     public void setValues(List<Float> values) {
         this.values = values;
     }
+
+    /**
+     * Convert the given object to string with each line indented by 4 spaces
+     * (except the first line).
+     */
+    private String toIndentedString(Object o) {
+        if (o == null) {
+            return "null";
+        }
+        return o.toString().replace("\n", "\n    ");
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder sb = new StringBuilder();
+        sb.append("SparseValuesWithUnsignedIndices {").append("\n");
+        sb.append("    indicesWithUnsigned32Int: ").append(toIndentedString(indicesWithUnsigned32Int)).append("\n");
+        sb.append("    values: ").append(toIndentedString(values)).append("\n");
+        sb.append("}");
+        return sb.toString();
+    }
 }