Improve extensions build. (#12461)

* enable ee build on pr/master

* step1: of including group sync

* disable commit pinning for now

* fixes broken build

* enable team to ldap group sync

* avoid returning error for missing external handler

* services: allow routes to be added before http server start

* services: allows services to add their own migrations

* moves db migrations to ee code base

* build using master branch in ee

* disable enterprise build in .bra.toml

[skip ci]

* removes team sync extensions

* removes commented line

public/app/core/config.ts

@@ -22,6 +22,7 @@ class Settings {
   disableUserSignUp: boolean;
   loginHint: any;
   loginError: any;
+  enterprise: boolean;
 
   constructor(options) {
     var defaults = {