#MM-12130 changes for custom service terms (#9450)

* #MM-12130 changes for custom service terms

* Fixed styling

* Added getServiceTerms API

* removed unnecessary panic

* removed custom service terms text from flat config

* reverted user sql store as those changes are no longer needed

* added tests

* Updated a config key to be more standard

* Added copyright info

* Loading service terms only if the feature is enabled

* Loading service terms only if the feature is enabled

* removed unused index

* added createservice termns API

* made a param to bool instead of string

* added createservice termns API

* review fixes

* fixed styling

* Minor refactoring

* removed saveConfig and loadConfig magic

* added empty service terms text check to createServiceTerms API

* refactoed some urls to be terms_of_service instead of service_terms

* removed check for support settings

* changed URLs in tests

* removed unused code

* fixed a bug

* added service termd id in conif

* fixed a test

* review fixes

* minor fixes

* Fixed TestCreateServiceTerms

store/sqlstore/upgrade.go

@@ -496,11 +496,11 @@ func UpgradeDatabaseToVersion54(sqlStore SqlStore) {
 	// if shouldPerformUpgrade(sqlStore, VERSION_5_3_0, VERSION_5_4_0) {
 	sqlStore.AlterColumnTypeIfExists("OutgoingWebhooks", "Description", "varchar(500)", "varchar(500)")
 	sqlStore.AlterColumnTypeIfExists("IncomingWebhooks", "Description", "varchar(500)", "varchar(500)")
-
 	if err := sqlStore.Channel().MigratePublicChannels(); err != nil {
 		mlog.Critical("Failed to migrate PublicChannels table", mlog.Err(err))
 		time.Sleep(time.Second)
 		os.Exit(EXIT_GENERIC_FAILURE)
 	}
+	sqlStore.CreateColumnIfNotExists("Users", "AcceptedServiceTermsId", "varchar(64)", "varchar(64)", "")
 	// 	saveSchemaVersion(sqlStore, VERSION_5_4_0)
 }