Migrate usage of wikibits in legacy protect.js and upload.js

Follows-up fcf4934a52.

protect:
* Use jQuery instead.
* Removing now-obsolete dependency.
* Make cell.appendChild more obvious and potentialy faster
  by grouping the dom actions in 1 sequence.

config:
* Removing obsolete dependency.

upload:
* Use jquery.spinner instead.
* Removing now-obsolete dependency.

jquery.spinner:
* While at it, updated documentation to be included in our
  jsduck index, similar to jquery.localize.

jsduck/external.js:
* Added @static to jQuery.ajax which was missing, it showed up
  between instance methods like jQuery#injectSpinner.

The only module left using mediawiki.legacy.wikibits is
mediawiki.legacy.ajax which remains in tact for now.

Bug: 56726
Change-Id: I712112626a99dc2d0090f554c56052770cd0ae88
(cherry picked from commit af4ef8153354b02ec910fd98ec7af024c64ab104)