feat: refresh token rotation configuration & github and facebook providers

[davenewza]

facebook and gitlab as built-in OpenID Connect providers

No need to provide issuer, token or auth URLs for Facebook and GitLab. They only need to be specified like this in the config:

  providers:
    - type: facebook
      name: fb_myapp
      clientId: 1234567

Refresh Token Rotation configureable

For some clients it may be important to disable refresh token rotation. When rotation is disabled, the original refresh token will be returned when minting a new access token. This can be done in the config as follows:

  tokens:
    accessTokenExpiry: 3600
    refreshTokenExpiry: 86400
    refreshTokenRotationEnabled: false. # <-- disable rotation

Other changes

• Improved reading from the config and dealing with default values
• Cleaned up some existing tests which made no more sense