[FRONT] user acceptance to join squad

[lulcca]

❗️ Check the label before starting task, it depends on this ❗️

Today we do not show the user that the invite of members to the squad is pending, as there is no email being send.
Once this is fixed, we need to reflect this on the page.

• (ux/ui) demonstrate that the user did receive the email but did not accept it yet on the squad users list (example: with a "(pending)" message by the side of its email and maybe with a lighter color font)
• (front) fix the squad users list on b-squad as the task above (ux/ui) implements and remove owner=true mocked param sent