Enable regex search (#4566)

* Adds custom search filter to allow 'regex' searching of results

* Specify if "shell" can access database for certain commands

* Bug fix for settings API

- Do not allow cache on detail endpoints
- Was causing strange error conditions with missing or duplicate PK values

* Adds user setting to control regex search

* Enable regex for search queries

- bootstrap tables
- search preview

* Pass search options through bettererer

* Refactor API endpoints to use new filter approach

* Bump API version

* Add "whole word" search

- Closes https://github.com/inventree/InvenTree/issues/4510

* Handle case where existing fields are empty

* pop > get

InvenTree/users/api.py

@@ -5,11 +5,12 @@ from django.core.exceptions import ObjectDoesNotExist
 from django.urls import include, path, re_path
 
 from django_filters.rest_framework import DjangoFilterBackend
-from rest_framework import filters, permissions, status
+from rest_framework import permissions, status
 from rest_framework.authtoken.models import Token
 from rest_framework.response import Response
 from rest_framework.views import APIView
 
+from InvenTree.filters import InvenTreeSearchFilter
 from InvenTree.mixins import ListAPI, RetrieveAPI, RetrieveUpdateAPI
 from InvenTree.serializers import UserSerializer
 from users.models import Owner, RuleSet, check_user_role
@@ -137,7 +138,7 @@ class UserList(ListAPI):
 
     filter_backends = [
         DjangoFilterBackend,
-        filters.SearchFilter,
+        InvenTreeSearchFilter,
     ]
 
     search_fields = [
@@ -168,7 +169,7 @@ class GroupList(ListAPI):
 
     filter_backends = [
         DjangoFilterBackend,
-        filters.SearchFilter,
+        InvenTreeSearchFilter,
     ]
 
     search_fields = [