Add support for more input sources in DirectoryReader (#283)

This adds support for listing TileDB groups

It also uses the same listing argument structure as the utilities used in VCF ingestion

Author: NikolaosPapailiou

apis/python/examples/object_api/text_search_documents.ipynb

@@ -80,9 +80,7 @@
     "vfs.create_dir(index_uri)\n",
     "\n",
     "reader = DirectoryTextReader(\n",
-    "        uri=documents_uri, \n",
-    "        glob=\"**/[!.]*\",\n",
-    "        config=config,\n",
+    "        search_uri=documents_uri,\n",
     "        text_splitter=\"RecursiveCharacterTextSplitter\",\n",
     "        text_splitter_kwargs={\"chunk_size\":1000}\n",
     "    )\n",