New client (because v1.3's is terrible to work with.)

Plan is to, with this, solve:

• Implement OAuth (or an OAuth-like service) #18 OAuth, sessions, and API keys can be configured in a new Access section under Account
• Add progress bar to uploading #7 Implement progress bars
• Invites #63 Suspensions #64 Better moderation tools than the ass ones that we have right now #28 New management panel, allowing admins to manage users, files, invites, etc...
• Light theme #33 (really themes in general)
• Implement a PWA for mobile users #39

I'll convert this to a PR once I publish the client-v2 branch.

A few ideas I want to implement:

• Default palettes: Catppuccin Mocha and Latte. Theming will follow the structure of Catppuccin's palette
• Sidebar instead of a topbar (by default.)
• OAuth, sessions, and API keys all merged into one "Access" section.
• Paginated file list(?)
• FAQ, TOS, privacy policy, and abuse contact, merged into one "instance information" panel
• Display total space used by files served
• Aforementioned "management" panel
• Disconnect the Logout button from Account and just place it directly in the topbar