Separate entry names from custom names, or rename thumbnails accordingly.

Description

When you rename a playlist entry though RetroArch, the thumbnails and information are lost, since RetroArch relies on the entry name for both. A simple solution would be to rename the thumbnail files automatically when the user renames an entry, but I don't know how the information works so I can't say anything on that.

Another would just be to add a custom label that is defined by the user, that doesn't touch anything about the entry itself. I think this is the most elegant option, since then you could name the file and the playlist entry however you want.

RetroArch already generates the entry using the No-Intro name regardless of the file name, meaning it detects exactly what ROM it is. I don't see why the thumbnails and information should rely on the entry name instead of that.

Expected behavior

The thumbnails and information stay as they are.

Actual behavior

The thumbnails and information disappear.

Steps to reproduce the bug

1. Import content.
2. Download thumbnails.
3. Rename the content's entry name.

Bisect Results

Has always been this way.

Version/Commit

You can find this information under Information/System Information

• RetroArch: cf6ca2a

Environment information

• OS: Android 9 and Windows 10 20H2.

Reproduce this in RetroArch by importing content, downloading thumbnails, and renaming the playlist entry; confirm that thumbnails and information disappear. Then trace the playlist-entry rename and thumbnail/information lookup paths, with completion defined as preserving those assets after an entry is renamed.