Closes #14740: Remove BootstrapMixin (#14841)

* 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

netbox/virtualization/forms/bulk_create.py

@@ -1,7 +1,7 @@
 from django import forms
 from django.utils.translation import gettext_lazy as _
 
-from utilities.forms import BootstrapMixin, form_from_model
+from utilities.forms import form_from_model
 from utilities.forms.fields import ExpandableNameField
 from virtualization.models import VirtualDisk, VMInterface, VirtualMachine
 
@@ -11,7 +11,7 @@ __all__ = (
 )
 
 
-class VirtualMachineBulkAddComponentForm(BootstrapMixin, forms.Form):
+class VirtualMachineBulkAddComponentForm(forms.Form):
     pk = forms.ModelMultipleChoiceField(
         queryset=VirtualMachine.objects.all(),
         widget=forms.MultipleHiddenInput()

netbox/virtualization/forms/model_forms.py

@@ -9,7 +9,7 @@ from extras.models import ConfigTemplate
 from ipam.models import IPAddress, VLAN, VLANGroup, VRF
 from netbox.forms import NetBoxModelForm
 from tenancy.forms import TenancyForm
-from utilities.forms import BootstrapMixin, ConfirmationForm
+from utilities.forms import ConfirmationForm
 from utilities.forms.fields import (
     CommentField, DynamicModelChoiceField, DynamicModelMultipleChoiceField, JSONField, SlugField,
 )
@@ -90,7 +90,7 @@ class ClusterForm(TenancyForm, NetBoxModelForm):
         )
 
 
-class ClusterAddDevicesForm(BootstrapMixin, forms.Form):
+class ClusterAddDevicesForm(forms.Form):
     region = DynamicModelChoiceField(
         label=_('Region'),
         queryset=Region.objects.all(),