Admins should be able to reset user's passwords

[josecelano]

Parent issue: #657

This only works if the user has an email (email can be optional). It should receive the new password via email.

[josecelano]

Relates to: #469

[josecelano]

Hi @da2ce7 @mario-nt I can't find any previous discussion about this issue, but I remember a discussion with @cgbosse. There was no way to reset user's password (by the user or admin) and I thought we should provide at least an easy/fast option to be able to use the Index in production (even if it's not a good option). I think we didn't even have the option to change the password in the user's profile. Now that we have that feature implementing issue #469 should be easier. Therefore we have to consider if this issue still makes sense. It could make sense in some scenarios like the ones we talked in the meeting:

• A user is misbehaving and the admin suspects that the account could be compromised (there could be other better alternatives like locking the account).
• The index is configured without emails and users can't not receive the new password or reset token. In this case, the issue would be different. We can't send an email.

[mario-nt]

Before implementing this issue we should do some research on best practices on how to manage resetting/changing passwords. It is a very critical action and could lead to a lot of security breaches if not done properly.

This also relates to #469