Add <supports_disc_control> tag for new Disc Manager

[garbear]

Description

This adds support for the new <supports_disc_control> tag required by the Disc Manager.

Related PRs:

Disc manager series:

• Game API v5.0.0: Disc Manager xbmc/xbmc#27984
• Game API v5.0.0: Disc control interface game.libretro#151
• Add <supports_disc_control> tag for new Disc Manager #138
• Update game add-ons for new Disc Manager LibreELEC/LibreELEC.tv#11065

How has this been tested?

Tested with pcsx-rearmed:

--- a/game.libretro.pcsx-rearmed/addon.xml.in
+++ b/game.libretro.pcsx-rearmed/addon.xml.in
@@ -18,6 +18,7 @@
 		<extensions>bin|cue|img|mdf|pbp|toc|cbn|m3u|chd|iso|exe</extensions>
 		<supports_vfs>false</supports_vfs>
 		<supports_standalone>false</supports_standalone>
+		<supports_disc_control>true</supports_disc_control>
 		<requires_opengl>false</requires_opengl>
 	</extension>
 	<extension point="xbmc.addon.metadata">

[garbear]

Add 100 add-ons have been updated with this change. Getting it in.