PLT-3695 refactoring to use sql_upgrader (#3788)

* PLT-3695 unitying upgrade support

* PLT-3695 refactoring to use sql_upgrader

* Fixing unit test

* Adding 3.3 to 3.4

* Fixing upgrading

* Seperating DB schema from version.go

* Fixing upgrade cmd

* Moving to const for exit codes

* remving old unused code

store/sql_audit_store.go

@@ -27,9 +27,6 @@ func NewSqlAuditStore(sqlStore *SqlStore) AuditStore {
 	return s
 }
 
-func (s SqlAuditStore) UpgradeSchemaIfNeeded() {
-}
-
 func (s SqlAuditStore) CreateIndexesIfNotExists() {
 	s.CreateIndexIfNotExists("idx_audits_user_id", "Audits", "UserId")
 }