Support for EZ Flash 3-in-1 in Flashcard version of TWLMenu

[MushGuyDS]

Is your feature request related to a problem? Please describe. This is related to certain GBA flashcarts not detected properly as GBA cartridges (this issue, for example), thus causing either TwilightMenu or the games to not load correctly (see also my issue), the EZ Flash 3-in-1 included.

Describe the solution you'd like With proper support of the device, the NDS games can be loaded with the 3-in-1 in its correct mode so that the latter can function properly with the game: Rumble mode for most NDS games, RAM Expansion mode for NDS Browser and homebrew apps that support it, GBA-DS Link Transfer for games like Pokémon. It could also add a second way to play GBA games besides using GBARunner2 by using real GBA hardware from the NDS. This will eliminate the need to use GBA Exploader to use most of these functions.

Describe alternatives you've considered If it can't be applied to TWLMenu, alternatively it could be applied to nds-bootstrap so that it can detect the 3-in-1 and use its correct mode properly.

Additional context The source code for the 3-in-1 is available through archive.org: https://web.archive.org/web/20210226043300/http://www.ezflash.cn/zip/512triplecardsrc.rar It can also be downloaded from here: https://web.archive.org/web/20200306092536/https://ezflash.sosuke.com/viewtopic.php?f=16&t=13482