my.youtube: use new my.google.takeout.parser module for its data

- fallback on the old logic if google_takeout_parser isn't available
- move to my.youtube.takeout (possibly mixing in other sources later)
- keep my.media.youtube, but issue deprecation warning
  currently used in orger etc, so doesn't hurt to keep
- also fixes https://github.com/karlicoss/HPI/issues/113

my/core/compat.py

@@ -83,3 +83,10 @@ def sqlite_backup(*, source: sqlite3.Connection, dest: sqlite3.Connection, **kwa
 
         dest.cursor().executescript(tempfile.read())
         dest.commit()
+
+
+# can remove after python3.9
+def removeprefix(text: str, prefix: str) -> str:
+    if text.startswith(prefix):
+        return text[len(prefix):]
+    return text