Fix Citron command line arguments handling

[felipecrs]

I wanted to pass -u 2 (to launch Citron with user 2), and noticed the flag was not being passed properly to the Citron executable.

I know a thing or two about Bash and noticed the Citron launcher script could use some improvement while also fixing this issue.

• Fix arguments being wrongly grouped after first " preventing other arguments like -u from working
• Pass -f -g flags from Steam ROM Manager to align with other emulators, rather than implicitly from Citron launcher script
• Optimize the Citron and Suyu launcher script, and remove unnecessary code
• Refactor all legacy "'${filePath}'" to "${filePath}" (all launchers are already prepared to handle it properly)

[felipecrs]

@dragoonDorise, I have verified these changes to be working in my own Steam Deck. In my opinion this PR is a no-brainer, but I'm happy to clarify each change if you want.