* 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
Move admin views for users, groups, and object permissions from the admin site to the NetBox frontend
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Co-authored-by: Jeremy Stretch <jstretch@netboxlabs.com>
