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>

config/utils.go

@@ -42,6 +42,10 @@ func desanitize(actual, target *model.Config) {
 		target.Office365Settings.Secret = actual.Office365Settings.Secret
 	}
 
+	if target.OpenIdSettings.Secret != nil && *target.OpenIdSettings.Secret == model.FAKE_SETTING {
+		target.OpenIdSettings.Secret = actual.OpenIdSettings.Secret
+	}
+
 	if *target.SqlSettings.DataSource == model.FAKE_SETTING {
 		*target.SqlSettings.DataSource = *actual.SqlSettings.DataSource
 	}