Update UI Icons

This updates Ryujinx's icons:

• (1) Added icons to certain missing Top Menu (Bar) & Game Options (right-click on game on the main screen)
  • e.g. File → Open Ryujinx Screenshots Folder now has an icon (in the form of a screen for a screen(shot))
• (2) Added icons to options which repeated both in the Top Menu and Game Options for consistency
  • e.g. Actions → Trim XCI Files and Game Options → Check and Trim XCI File perform similar (same) operation, so both have the same icon (scissors)
• (3) Changed icons to better communicate certain actions
  • e.g. Help → Open Compatibility List had a gamepad icon, which was relatively small. Now, it has a database icon to clearly show it is a compatibility "database"
    • Also has been changed in the Game Options → Show Compatibility Entry, as per (2)
• (4) Changed icons where the little details weren't necessarily clear to the naked eye
  • e.g. Game Options → Cache Management → Purge PPTC cache & Purge Shader Cache both had trash cans with an "!" on the side, which was very small, so both now have a simple trash can
• (5) Changed GitHub icons to GitLab icons in the Help → FAQ & Guides options
  • Development ceased on GitHub (also, the links point to wiki's & guides on GitLab, not GitHub), so self-explanatory
• (6) Changed all mdi icons to fa (Font Awesome) icons
  • mdi icons were small while fa icons were bigger and many options already used fa icons. Furthermore, this change doesn't hinder the UX (as the actions are already clear and the tooltips clarify them further) and improves the UI as there is more visual consistency in icon size and style
  • Additionally ensured that, if icons repeated, they repeated within their respective mini-groups.
    • e.g. Menu Bar folder icons for File → Open Ryujinx Folder is the same as the icons for Actions → Install Keys/Firmware → Install Keys/a firmware from a directory. However, for Game Options → Open Mods Directory/Open Atmosphere Mods Directory is the same folder icon as Game Options → Cache Management → Open PPTC Directory and Open Shader Cache Directory. So they are the same for their mini-groups, while still being relatively unique

I'm attaching some screenshots of the before/after (left/right, respectively) to show how the options will look.

"File" Menu Options :

"Options" Menu Options (haha):

"Actions" (Out Of Game) Menu Options (Same for "Install Firmware):

"Actions" (In Game) Menu Options (Changed the "Take Screenshot Icon" to a Camera – see below in comments):

"Help" Menu Options:

Game Options (Right Click On Game):