refs #332

refs #115

This changes enables us to catch typos as well as missing or updated
steering permissions in the dashboard code.

This refactoring includes some fixes, new features,
and updates to the API:

* the new /media and /media-sources APIs are used
* users can now cancel the addition of new media sources
* all errors should now be catched and displayed, no matter when
  in the handling process they happen
* users can show the import logs for uploads
* uploads happen in the background so users can move to
  other pages without aborting the upload

refs #347
refs #328
refs #323
refs #342
refs #273

refs #343

refs #343

This was confusing for users.

refs #310

refs: #327

The preceding revert commit erroneously removed the focus-trap
dependency.

The anchor-positioning polyfill doesn’t properly work with dynamic
elements and re-applying styles every time dynamic elements are rendered
is too brittle.

See: https://github.com/oddbird/css-anchor-positioning/issues/91

This reverts commit ffe576b1.

refs #318

This commit removes the old note handling and replaces it with the new
timeslot-independent episodes.

refs #317

When setting representation to 'date' it is likely that the setter value
is a simple date (YYYY-MM-DD) as well. This fix accounts for that.

refs tank#81
refs #316

Co-Authored-By: Alex Gorji <ag@roko.li>