feat: Add initial AuthzQuerier implementation (#5919)

feat: Add initial AuthzQuerier implementation
- Adds package database/dbauthz that adds a database.Store implementation where each method goes through AuthZ checks
- Implements all database.Store methods on AuthzQuerier
- Updates and fixes unit tests where required
- Updates coderd initialization to use AuthzQuerier if codersdk.ExperimentAuthzQuerier is enabled

coderd/users_test.go

@@ -854,7 +854,7 @@ func TestGrantSiteRoles(t *testing.T) {
 			AssignToUser: randOrgUser.ID.String(),
 			Roles:        []string{rbac.RoleOrgMember(randOrg.ID)},
 			Error:        true,
-			StatusCode:   http.StatusForbidden,
+			StatusCode:   http.StatusNotFound,
 		},
 		{
 			Name:         "AdminUpdateOrgSelf",