RFE: icons in playlists with custom names

First and foremost consider this:

• Only RetroArch bugs should be filed here. Not core bugs or game bugs
• This is not a forum or a help section, this is strictly developer oriented

Description

From thinking about for a bit, I understand the likely reason why playlists depend on filename instead of a internal property to load the main icon, is to be able to load icons before parsing playlists when entering the playlist tab so there are no delays.

But I'd still like to have custom names and a icon. Therefore I'd like to propose a rfe to ignore text added after a filename match when starting from 0.

For instance, you could name a playlist the custom names:
Sony - Sony PlayStation (Japan)
Sony - Sony PlayStation (Hacks)
Scummvm (AGS)

And to match the icon only the bolded part would be considered, while still allowing playlist theme divisions with icons.

Expected behavior

At first I expected this could be done more systematically and without forcing (part) of a filename by modifying the playlist JSON format, but finally understood the filename requirement was likely about the playlist tab responsiveness and not being forced to parse playlists before displaying icons, so came to this alternative idea.

It has the advantage of keeping same system icons near each other on the sort order

Actual behavior

Custom playlist names have the default icon, with absolutely no way to avoid it if you want custom theme playlists or want to divide subsystems.

No source file or test is named. Start by tracing the playlist tab's icon matching and playlist-name handling in the C frontend, then determine how matching can ignore the proposed suffix without adding playlist parsing delays. Done means custom-named playlists use the matching base icon while retaining responsive playlist display.