add streaming_url to file api response type

lbrynet/extras/daemon/json_response_encoder.py

@@ -67,6 +67,7 @@ def encode_account_doc():
 
 def encode_file_doc():
     return {
+        'streaming_url': '(str) url to stream the file using range requests',
         'completed': '(bool) true if download is completed',
         'file_name': '(str) name of file',
         'download_directory': '(str) download directory',

lbrynet/stream/managed_stream.py

@@ -213,6 +213,7 @@ class ManagedStream:
             download_directory = None
             written_bytes = None
         return {
+            'streaming_url': f"http://{self.config.api_host}:{self.config.api_port}/stream/{self.sd_hash}",
             'completed': (self.output_file_exists and self.status in ('stopped', 'finished')) or all(
                 self.blob_manager.is_blob_verified(b.blob_hash) for b in self.descriptor.blobs[:-1]),
             'file_name': file_name,