Add a new Password Reset Event

[mrioan]

Our RequestEventListener should be updated to include a PasswordResetRequestEvent denoting that a successful reset password has just taken place.

[mrioan]

Obtaining a successful reset notification is actually not achievable since the last step (actual reset) is done by the backend. We could only be notified about a reset password request but not about its final outcome. Not sure if this is still a relevant event users will be interested in. I'll keep this issue open for discussion.