Issue with adding and managing multidisk games

[Kupo91]

In some emulators it's common to use *.m3u playlists to handle multidisk games. Examples for emulators which use these files are Beetle PSX (PS1), Kronos (Sega Saturn), Flycast (Dreamcast) and Dolphin (Gamecube/Wii).

There are different reasons why it's recommended to use *.m3u files. But the issue with RCB is the following:
Let's say our ps1 roms have the extensions *.bin and *.cue. Additionally multidisk games have a *.m3u file, which you want to use to launch multidisk games (so these are also the files which should be imported by RCB).
If you want to import singledisk games you would have to add *.cue as file extension to your rcb config.
If you want to import multidisk games you would have to add *.m3u as file extension to your rcb config.
If you have both singledisk and multidisk games you would need both of them.

If the RCB option "Use foldername as gamename" is disabled RCB creates multiple entries for multidisk games (one entry for each disk and the m3u file).
If the option is enabled it only creates one entry per game (which is good), but the issue is that it doesn't import the *.m3u file but the *.cue file of disk 1.

So what RCB would need is the ability to look for *.m3u files first and then stop looking for any further files.