MM-27688-OpenId Connect (#16222)

* implement openid connect

* update error strings

* handle OpenIdSetting.Secret as FAKE SETTING

* add openid to telemetry

* update config defaults, add telemetry

* fix bug with Office365

* Retrieve Office365 AuthData from IdToken

* fix linter

* add feature flag, reset defaults for config

* fix build error

* fix unit tests

* add authentication permission to Feature
Flags

* turn off feature flag

* set default button color

* set default button color only on openid

* fix for merging FeatureFlags in config

* remove feature flag

* revert config changes

* remove debug statements

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

einterfaces/oauthproviders.go

@@ -10,7 +10,9 @@ import (
 )
 
 type OauthProvider interface {
-	GetUserFromJson(data io.Reader) (*model.User, error)
+	GetUserFromJson(data io.Reader, tokenUser *model.User) (*model.User, error)
+	GetSSOSettings(config *model.Config, service string) (*model.SSOSettings, error)
+	GetUserFromIdToken(idToken string) (*model.User, error)
 }
 
 var oauthProviders = make(map[string]OauthProvider)