Fix type-checking errors in snippets (code only, no .md)

This commit both:
- Fixes pre-existing mistakes in snippets, aka wrong code samples.
- Adds hidden (`@hide`) statements that do not appear in the docs,
  but satisfy typecheckers.

qdrant-landing/content/documentation/headless/snippets/insert-points/with-tenant-group-id/go.go

@@ -12,6 +12,8 @@ func Main() {
 		Port: 6334,
 	})
 
+	if err != nil { panic(err) } // @hide
+
 	client.Upsert(context.Background(), &qdrant.UpsertPoints{
 		CollectionName: "{collection_name}",
 		Points: []*qdrant.PointStruct{

qdrant-landing/content/documentation/headless/snippets/insert-points/with-tenant-group-id/java.java

@@ -1,5 +1,9 @@
 package com.example.snippets_amalgamation;
 
+import static io.qdrant.client.PointIdFactory.id;
+import static io.qdrant.client.ValueFactory.value;
+import static io.qdrant.client.VectorsFactory.vectors;
+
 import io.qdrant.client.QdrantClient;
 import io.qdrant.client.QdrantGrpcClient;
 import io.qdrant.client.grpc.Points.PointStruct;