Adds a id_attribute to the GenericOAuthProvider, which is used to map the external User. Further mapping can be done in actions by using the `rawInfo` of the new `ctx.v1.providerInfo` field.
Add management functionality for LDAP idps with templates and the basic functionality for the LDAP provider, which can then be used with a separate login page in the future.
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Co-authored-by: Livio Spring <livio.a@gmail.com>