feat(ctr): Bundling, optimise assets, page weight/memory improvements

[ashquarky]

Resolves #XXX

Changes:

• Bundle ctr code. This allows for tree shaking etc. Including Pjax with the bundler also means one less http request during page load.
• Only deliver debug.js to non-console UAs. It had a check in it to do nothing on console, so why download the 25KiB?
• Re-created various images and theme assets to compress better. Stylesheet goes from 82KiB to 37KiB. Also included the raw assets in the repo, in case we swap to a better system of inlining.
• Calls cave.requestGc after PJAX page loads. This is supposed to help alleviate RAM issues on O3DS a bit, but more probably needs doing.

• I have read and agreed to the Code of Conduct.
• I have read and complied with the contributing guidelines.
• What I'm implementing was an approved issue.
• I have tested all of my changes.

[ashquarky]

Before:

After:

Note this was done without working CDN, so the real page weight is a lot more from all the images, but that's a different PR :)

[mrjvs]

looks good!