[`media`] Added `media.get_info` action.

It combines the `-j` and `-g` options of ytdl* to get both the stream
URL and the track metadata.

platypush/plugins/media/__init__.py

@@ -1,6 +1,7 @@
 import enum
 import functools
 import inspect
+import json
 import os
 import queue
 import re
@@ -283,7 +284,7 @@ class MediaPlugin(Plugin, ABC):
         """
 
         if self._is_youtube_resource(resource):
-            resource = self.get_youtube_video_url(resource)
+            resource = self._get_youtube_info(resource).get('url')
         elif resource.startswith('magnet:?'):
             self.logger.info(
                 'Downloading torrent %s to %s', resource, self.download_dir
@@ -589,7 +590,7 @@ class MediaPlugin(Plugin, ABC):
         assert response.ok, response.text or response.reason
         return response.json()
 
-    def get_youtube_video_url(self, url, youtube_format: Optional[str] = None):
+    def _get_youtube_info(self, url, youtube_format: Optional[str] = None):
         ytdl_cmd = [
             self._ytdl,
             *(
@@ -597,16 +598,21 @@ class MediaPlugin(Plugin, ABC):
                 if youtube_format or self.youtube_format
                 else []
             ),
+            '-j',
             '-g',
             url,
         ]
 
         self.logger.info('Executing command %s', ' '.join(ytdl_cmd))
         with subprocess.Popen(ytdl_cmd, stdout=subprocess.PIPE) as ytdl:
-            url = ytdl.communicate()[0].decode().strip()
+            output = ytdl.communicate()[0].decode().strip()
             ytdl.wait()
 
-        return url
+        stream_url, info = output.split('\n')
+        return {
+            **json.loads(info),
+            'url': stream_url,
+        }
 
     @staticmethod
     def get_youtube_id(url: str) -> Optional[str]:
@@ -632,7 +638,7 @@ class MediaPlugin(Plugin, ABC):
         youtube_id = self.get_youtube_id(url)
         if youtube_id:
             url = f'https://www.youtube.com/watch?v={youtube_id}'
-            return self.get_youtube_video_url(url, youtube_format=youtube_format)
+            return self._get_youtube_info(url, youtube_format=youtube_format).get('url')
 
         return None
 
@@ -648,6 +654,13 @@ class MediaPlugin(Plugin, ABC):
 
             return proc.stdout.read().decode("utf-8", "strict")[:-1]
 
+    @action
+    def get_info(self, resource: str):
+        if self._is_youtube_resource(resource):
+            return self.get_youtube_info(resource)
+
+        return {'url': resource}
+
     @action
     def get_media_file_duration(self, filename):
         """