* REFACTOR: reworks all the search-advanced-options panel
This commit includes the following changes:
- prevents any mutation of external (to the component) values
- get rid of observers
- uses @action
- minor UI tweaks
- dropped the unecessary debounce
- drops all the legacy code for badges/groups which is not being used
- replaces user-selector by user-chooser and improves multi-select to not show `search` if maximum has been reached
Most importantly this refactor should fix multiple bugs due to _update() being called multiple times if searchTerm was empty and other various bugs where some changes in searchTerm was not applied to the sidebar.
This reverts commit 20780a1eee.
* SECURITY: re-adds accidentally reverted commit:
03d26cd6: ensure embed_url contains valid http(s) uri
* when the merge commit e62a85cf was reverted, git chose the 2660c2e2 parent to land on
instead of the 03d26cd6 parent (which contains security fixes)
