Allow to get all accounts instead of the "current account or passed account"

Problem/Motivation

Currently not possible to "easily" get all accounts.
Currently we have:

  public function getAccounts($plugin_id, $user_id = NULL) {
    $storage = $this->entityTypeManager->getStorage($this->entityType);

    if (!$user_id) {
      $user_id = $this->currentUser->id();
    }

    // Get the accounts associated to the user.
    $accounts = $storage->loadByProperties([
      'user_id' => $user_id,
      'plugin_id' => $plugin_id,
    ]);

    return $accounts;
  }

Only allows filtering on a certain ID (or the current one)

Steps to reproduce

/

Proposed resolution

Allow to get all.

Remaining tasks

Review merge request