convert platform enum to an array of strings to allow custom platform support

[jmshgs]

It'd be nice if the user could add custom platforms. For example, there is already a PS platform, but the user could delete that and separate it into PS1 and PS2. Then they could link emulators and commands for launching games in them to each so then when they select the platform as PS1, it could automatically create a command that opens the game in Duckstation or something

[jmshgs]

for this we must change the data type of platforms to an array of strings instead of an enum so the user is able to add new platforms.

[jmshgs]

instead of using array of strings, we could use an array of structs for a new Platform type.

struct Platform {
  var name: String
  var icon ???? idk
  var linkedEmulator / linkedApp

or not even that but a command template string for a emulator but phoenix should make the command. u provide emulator and phoenix gives ui like:

• [ ] fullscreen
• [ ] no gui

something like that

[jmshgs]

done in 3ec7782c5f5c2f270ebd55723de85441978666c4