Ability to resend invitation mail to registered users

Description of the limitation and why it is relevant to address

It would be very useful to under the action button in the users tab be able to select an option to resend the invitation email to a user that has been invited but not yet registered.

Submitter proposed design (optional)

None

Current workarounds

Delete the user and re-add the user to the environment

Nice! @tvantil @StijnJ