* Modified how we do Select2 dynamic drop-down menus to be more secure
As noted by the author of select2, the more-secure way of creating
rich Select-dropdowns is to use jquery to create HTML snippets and
carefully modify text attributes within there. This prevents any
XSS from being brought to the page. As a side-effect, the extra
escaping that we had to do in all of the internal selectlist calls
is now no longer necessary, and has been removed. Rebased and
squashed from the original.
* Rebuilt all assets, but this still feels like it's too much stuff in here.
* Whoops, need to run that in dev, not prod
* adds select2 placeholders to select lists
To allow us to clear the selection on „select2“ selects, we need a placeholder attribute
See: https://select2.org/placeholders
* Removes empty option from multiple select
select2 requires an empty option value on singular selects, but not on multiple selects.
When selecting multiple options, this empty option would be shown as selectable otherwise, not clearing the selection.
* Adds the option to clear select2 instances
Sets the correct options to allow clearing of out select2 instances. The empty placeholder is required, since clearing only works when a placeholder ist set (event an empty one).
See: https://select2.org/placeholders
* Removes the „Clear selection“ option from select lists
Since we can clear the select2 lists with their native clearing method, we can remove this hack
* Updates generated assets (css/js)