Revamp Studio UI

[rjindael]

• [ ] Use FamFamFam icon spritesheet (famfamfam-silk provides an excellent spritesheet with offsets included; simple RegEx to make that a std::vector<string, int[2]> :P)
• [ ] Extract Roblox resources to get their icons (and we don't have to include it on our repo!)
• [ ] Use CSS, less barebones
• [ ] Somewhat of a ribbon with a proper toolset (drag, resize, move, etc.)
• [ ] A nice color picker
• [ ] Overall pleasant to use on BOTH platforms

[floralrainfall]

Rewriting the UI in Qt6 .ui files would probably be better then just inserting widgets manually