* Experimenting
* Remove testing resources
* Replace ApiSelect with TomSelect
* Add color support
* Add clear button
* Clear cached options when searching dynamic selects
* Add support for static parameters
* Refactor TomSelect implementation
* Add dynamic parameter support
* Limit number of options to 100
* Remove redundant api_url definitions for user model
* Add support for disabled indicator
* Remove obsolete value-field attr on dynamic select widgets
* Remove obsolete fetch_trigger kwarg from dynamic model choice widgets
* Remove obsolete empty_label kwarg from dynamic model choice widgets
* Add support for API path variables
* Add support for setting a 'null' option
* Annotate depth for recursive hierarchies
* Misc cleanup
* Remove obsolete APISelect code
* Remove slim-select & just-debounce-it
* Clean up type validation
* Closes#14237: Clear child selections on change to parent selection
* Use an MD icon for the clear button
* Use an MD icon for the clear button
* Explain why noUnusedParameters is disabled
* Introduce custom form widget templates to apply CSS classes
* Apply both mandatory and optional CSS classes to form widgets
* Omit required & placeholder attrs
* Move annotation of field validation failures to CSS
* Remove BootstrapMixin class
* Remove obsolete ComponentTemplateImportForm class
* Remove obsolete custom forms for login & password change
* Clean up obsolete accommodations for 'required' widget attr
