Replace (some) jQuery code with native javascript

[richardebeling]

These places are left, but they will have to be done in separate PRs:

• Student voting page and sisyphus.js -- Sisyphus is based on jQuery, we'd probably have to replace it?
• sortable_form_js.html / makeFormSortable / rowChanged / rowAdded -- I think this is enough for a separate PR.
• bootstrap datetimepicker seems to be a jQuery-thing. Is there maybe a native alternative by now?
• confirmation_text_modal.html and confirmation_modal.html -- @niklasmohrin is working on these and I don't know how to efficiently replace the unbind method call.

Todo:

• templates/base.html still has jQuery usages in 172--178
• evap_evaluation_edit_js.html
• A few places had a fade-out-then-delete behavior. We want to get the fadeout back (search for slow in changes)
• @niklasmohrin How to we want to make universal typescript helper functions available to templates? Currently, this affects assert and fadeOutThenRemove from utils.ts and CSRF_HEADERS from csrf_utils.ts. base.html includes utils to make these available globally.

[niklasmohrin]

I don't think we can replicate unbind easily. If I understand correctly, it is only used to capture the data id variable, so a possible replacement would be to have a variable that the "show" handler updates. The unbind-bind then just becomes a single bind outside of the "show" handler

[niklasmohrin]

If you want, you can also leave the modals unchanged and I take of them in the other PR. I havent exactly figured out how to deal with the "shared modals" business yet and wanted to think about that later, so if you have ideas / solutions I will gladly take them

[richardebeling]

Yeah I decided that I will not bother with the actual base modal implementation in this PR, since that's what you are currently changing.

[niklasmohrin]

The globalThis solution seems fine for now, we can think about it in another PR

[niklasmohrin]

Looks mostly good, some nits: