Allow OAuth-SSO also when form is available

[mheers]

Description

This PR allows the single-sign-on via OAuth even when formAuth is also available.

To have the API working with username/password we need to enable formAuth. When a user also configures OAuth the user could never login using this SSO because the form was prioritized.

Additional context and related issues

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* Allow OAuth-SSO also when form is available

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[oneonestar]

Maybe we should use AuthenticationConfiguration.defaultType to decide which loginType to be used.

[oneonestar]

@cla-bot check

[cla-bot]

The cla-bot has been summoned, and re-checked this pull request!

[oneonestar]

Maybe we should use AuthenticationConfiguration.defaultType to decide which loginType to be used.

@mheers Any thoughts?

[mosabua]

I think it might be best to look how this is handled in Trino and then just do the same thing.

[willmostly]

@mheers are you still interested in working on this?