Make "Invite new people" always possible for Admins

[yurabakhtin]

What kind of change does this PR introduce? (check at least one)

• Bugfix

The PR fulfills these requirements:

• All tests are passing
• Changelog was modified

Other information:
https://github.com/humhub/humhub-internal/issues/225

[what-the-diff]

PR Summary

• Improvment of Admin Access
  We implemented a solution that consistently allows Admins to "Invite new people" as stated in the CHANGELOG.md. This update enhances the administrative functionality and offers greater flexibility to Admins.

• Form Import Update
  There's an addition of a new import for the Invite form within the UserController.php. This import enhances usability and efficiency when initiating the invitation process to new users.

• Render Parameters Adjustment
  By updating the render parameters in the actionAdd function in UserController.php, we've made the operation smoother and are avoiding possible exceptions that could disrupt user activity.

• Data Action-URL Modification
  We made an update to the data-action-url in the invite/index.php file. This contributes to making the process of inviting new people through the user interface simpler, and less prone to issues or mistakes.