core: Replace legacy INI config system with Pydantic-based TOML configuration.

This is a huge configuration refactoring.

The configuration system now uses Pydantic settings, with better validation, better
support for environment variables and other goodies.

The main config files now use TOML instead of INI, this allow for better handling of
complex types, notably dict.

Plugins, components and frontends can declare their config settings in a class which will
be imported dynamically.

libervia/backend/plugins/plugin_misc_android.py

@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 # SAT plugin for file tansfer
 # Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)
 
@@ -30,6 +28,7 @@ from twisted.internet import protocol
 from twisted.internet import abstract
 from twisted.internet import error as int_error
 from twisted.internet import _sslverify
+from libervia.backend import G
 from libervia.backend.core.i18n import _, D_
 from libervia.backend.core.constants import Const as C
 from libervia.backend.core.log import getLogger
@@ -284,7 +283,7 @@ class AndroidPlugin(object):
         self.am = activity.getSystemService(Context.AUDIO_SERVICE)
 
         # sound notification
-        media_dir = Path(host.memory.config_get("", "media_dir"))
+        media_dir = G.config.common.media_dir
         assert media_dir is not None
         notif_path = media_dir / "sounds" / "notifications" / "music-box.mp3"
         self.notif_player = MediaPlayer()