Is your feature request related to a problem? Please describe.
Using the Custom OAUTH Provider dialog i am unable to utilize Office 365 as a provider. The authentication does work but i cannot map the username field to the UPN since the '@' symbol is not allowed for users. This does work if i omit a username field but i would like to keep the usernames uniform for a SSO experience and to merge users.

Describe the solution you'd like
Create a OAUTH provider for Office365. This would be able to map the username by parsing the UPN string before the '@' symbol which is the valid samAccountName. The Full Name can be mapped by merging the 'given_name' and 'family_name' values. the E-mail address can be mapped straight form the upn.

Describe alternatives you've considered
I tried adding additional claims in the ID Token, Rocket.Chat cannot parse optional claims due to the structure of the JWT

Additional context
Just trying to keep this concern alive. A lot of companies use Office365 for SSO.