[permissions] Update updateRole logic + disallow self role-assignment (#10476)

In this PR

- updateWorkspaceMemberRole api was changed to stop allowing null as a
valid value for roleId. it is not possible anymore to just unassign a
role from a user. instead it is only possible to assign a different role
to a user, which will unassign them from their previous role. For this
reason in the FE the bins icons next to the workspaceMember on a role
page were removed
- updateWorkspaceMemberRole will throw if a user attempts to update
their own role
- tests tests tests!

packages/twenty-server/src/engine/metadata-modules/permissions/utils/permission-graphql-api-exception-handler.util.ts

@@ -14,6 +14,7 @@ export const permissionGraphqlApiExceptionHandler = (
   switch (error.code) {
     case PermissionsExceptionCode.PERMISSION_DENIED:
     case PermissionsExceptionCode.CANNOT_UNASSIGN_LAST_ADMIN:
+    case PermissionsExceptionCode.CANNOT_UPDATE_SELF_ROLE:
       throw new ForbiddenError(error.message);
     case PermissionsExceptionCode.ROLE_NOT_FOUND:
     case PermissionsExceptionCode.USER_WORKSPACE_NOT_FOUND: