Revamp store UI

[Commenter25]

Where do I even begin? I practically redid the whole thing. It really needed it.

Comparison images (600kb)

Screenshots taken with PR #193 merged, so there's actual icons to look at. Wowozela screenshots were taken with my open PR to add an icon and description. I also temporarily disabled Run for a more complete screenshot, but this is not in the PR.

The upgrade menu had nowhere near as drastic of a change: besides the sorting change, it's really just the padding, increasing the gradient size, and moving everything a littler further from the gradient.

Before:

After:

Also added a whole new sound for buying things. I would embed it here but GitHub won't let me because they are too cowardly to support the super obscure rarely used MP3 format. It plays serverside for all players to hear you spending your life savings, and after the first purchase it'll randomly shift in pitch. A different sound (hl2 buttons/button10.wav) plays when purchase failed, clientside with no pitch shifting.

Besides what's obvious above, here's a list of All The Things I Did:

• Got rid of absurd whitespace hackiness, including in the localization files
• Items are now sorted by thirdparty, purchased, number of requirements, and price. Upgrades were only changed to go alphabetically top down instead of bottom up
• Added tooltip for already purchased items, and made requirement tooltip not scream so much
• Icons are now perfect squares
• Icons are now dynamically smoothed and mipmapped (slightly blurry but far more appealing than jagginess imo)
• Fixed Stan showing short description in store (this only matters with Add custom weapon icons #193) (kept fixed in old screenshot for better comparison)
• Changed spawnmenu name and description (not changed in old screenshot because i forgot and didn't care enough to redo it)
• Uncategorized upgrades (upgrades without a base unlock) can now be added, and will appear at the top above all the categories
• Fixed bug where only one spacer could be rendered in upgrades
• Window dynamically sizes to fit a smaller store, maxes out at a reasonable height
• Abstracted some duplicated stuff into shared functions
• Got rid of secret little button icons hiding behind the big icons
• I cleaned up whitespace in thirdparty.lua because I don't think it'll ever be touched or thought about again and I might as well do it now

Also, happy #200! I'd like to think this is worthy of it.