[Feature] Forgot Password Dialog and Girder API connection

[BryonLewis]

Would be nice if the login had the option to use a new dialog in the same GWC style for a forgot password instead of kicking them to the girder default password request. Just a simple dialog that called the /user/password/temporary with their input email and supplied back if the input email was correct and a temporary password sent.

In some apps it's nice to keep the user unaware of Girder itself so they are presented with a unified interface. Now I realize this is something that could be done using the forgotpassword signal from Login.vue->Authentication.vue but feel that it might be more broad than just the app I'm working on.