feat(oauth): allow wildcards in redirect_uris

[abulte]

This add a setting and logic to allow wildcards in redirect_uris for an OAuth2Client.

On Ecosphères, it will be very useful to be able to use OAuth when testing PR previews that have URLs like https://deploy-preview-205--ecospheres.netlify.app. We could authorize *ecospheres.netlify.app/login/callback for our client.

Since this might be dangerous security-wise, it's behind a flag that is False by default. I suggest enabling it only on dev/demo instances and not in production.

[maudetes]

Nice! Seems secure enough with default flag indeed.

Since it's a hassle to test it correctly locally, if you update the branch I can deploy it on our demo env before merging :)

[abulte]

@maudetes updated! FYI I tested locally with a *.local pattern and ecospheres-front, but it never hurts to check again.