Add OAuth2 authentication for use in outlook365.com

[phochstr]

Dear @ivy-sgi, it would be cool to have the following feature in the market place:

Is your feature request related to a problem? Please describe.
With the current version, we cannot connect to Microsoft 365 mailstores because they require OAuth2 authentication while we only support Basic Authentication.

Describe the solution you'd like
Implement OAuth2 authentication compatible with Microsoft 365 (see https://support.microsoft.com/en-us/office/pop-imap-and-smtp-settings-for-outlook-com-d088b986-291d-42b8-9564-9c414e2aa040)

Describe alternatives you've considered
We checked that the connector works correctly with traditional Basic Authentication against another mail provider.

Additional context
A customer tried to access Outlook365 and got an auth error; see #5081

[ptanhaxon]

Hi @phochstr ,
We are in progress of the implementation for this use case because we really need OAuth2 Authen for MailStore in our project HDS. Customer does not provide the app password due to security reason. Tracking ticket: https://1ivy.atlassian.net/browse/MARP-1189
cc @kimthanh175 @nvvi

[phochstr]

Hi @ptanhaxon

Thanks for letting me know. I informed the customer and linked this issue as well as the original Zendesk ticket to your internal ticket.