Remove jQuery

[ArtOfCode-]

Removes the jQuery dependency from our code - see #1429.

WIP: Re-write scripts to use vanilla JS instead of jQuery.

Once scripts are rewritten we can remove the dependency itself.

Help wanted!

TODO LIST - please tick a file if you're about to review & update it so we don't duplicate work.

• micro_auth/apps.js
• admin.js
• application.js
• caret.js (utility, no update needed)
• categories.js
• character_count.js
• closure.js
• codeblocks.js
• comments.js
• donations.js
• embed.js
• filters.js
• flags.js
• keyboard_tools.js
• latex_escape.js (utility, update not required)
• licenses.js
• markdown.js
• mod_warning.js
• modals.js
• moderator.js
• notifications.js
• post_histories.js
• posts.js
• preferences.js
• privileges.js
• qpixel_api.js
• qpixel_dom.js
• reactions.js
• search.js
• site_settings.js
• subscriptions.js
• suggested_edits.js
• tag_sets.js
• tags.js
• textarea_popup.js
• tour.js
• two_factor.js
• users.js
• votes.js

[ArtOfCode-]

Slight roadblock: rails-ujs also depends on jQuery. This powers things like remote links/forms, which we use a bunch of. It's not impossible to replace, but it's a bunch more work.

My strategy at the moment is going to be to start by converting everything that doesn't use rails-ujs, leaving those bits as jQuery for the moment.

[ArtOfCode-]

Roadblock number 2: we use select2 for our interactive <select> elements, which is a jQuery plugin.