feat: support for filtering only "files" in get_all_files API (#1556)

Author: nikkothari22

raven/api/raven_message.py

@@ -449,6 +449,8 @@ def get_all_files_shared_in_channel(
 	if file_type:
 		if file_type == "image":
 			query = query.where(message.message_type == "Image")
+		elif file_type == "file":
+			query = query.where(message.message_type == "File")
 		elif file_type == "pdf":
 			query = query.where(file.file_type == "pdf")
 		else: