Migrate masquerade permissions from D7 to D9.

Tested manually and masquerade as adminpermission is properly migrated to masquerade as super user.

Masquerade as any user permission is already migrating properly because of same name in D7 & D9.

Other permissions changed between D7/9 and needs to be updated manually.

+++ b/masquerade.module
@@ -244,3 +244,13 @@ function masquerade_switch_user_validate(UserInterface $target_account) {
+function masquerade_migration_plugins_alter(array &$migrations) {
+  $migrations['d7_user_role']['process']['permissions'][0]['map']['masquerade as admin'] = 'masquerade as super user';
+}

I have only a tiny-tiny nit, but I feel it can be important:

Could you please wrap this into a condition which checks/verifies that the first process plugin configuration of the permissions destination property is a static_map plugin?

function masquerade_migration_plugins_alter(array &$migrations) {
  if (
    !empty($migrations['d7_user_role']['process']['permissions'][0]) &&
    $migrations['d7_user_role']['process']['permissions'][0]['plugin'] === 'static_map'
  ) {
    $migrations['d7_user_role']['process']['permissions'][0]['map']['masquerade as admin'] = 'masquerade as super user';
  }
}

Looks good to be committed but I'm afk next days

merged, thanks