feat: omitExtensionCreation is added to PostgresVectorDatabase.cs (#33)

* Option to omit Extension creation

Since not all DB admins like to share SU roles to access applications.

* omitExtensionCreation filed added to PostgresVectorDB file

Making sure that the parameter can be passed from the actual creation point.

* Update PostgresVectorDatabase.cs

src/Postgres/src/PostgresVectorDatabase.cs

@@ -12,12 +12,13 @@ namespace LangChain.Databases.Postgres;
 [RequiresUnreferencedCode("Requires unreferenced code.")]
 public class PostgresVectorDatabase(
     string connectionString,
-    string schema = PostgresVectorDatabase.DefaultSchema)
+    string schema = PostgresVectorDatabase.DefaultSchema,
+    bool omitExtensionCreation = false)
     : IVectorDatabase
 {
     private const string DefaultSchema = "public";
 
-    private readonly PostgresDbClient _client = new(connectionString, schema);
+    private readonly PostgresDbClient _client = new(connectionString, schema, omitExtensionCreation);
 
     /// <inheritdoc />
     public async Task<IVectorCollection> GetCollectionAsync(string collectionName, CancellationToken cancellationToken = default)
@@ -67,4 +68,4 @@ public Task<IReadOnlyList<string>> ListCollectionsAsync(CancellationToken cancel
     {
         return _client.ListTablesAsync(cancellationToken);
     }
-}
+}