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

scripts/build/build_enterprise.sh

@@ -14,9 +14,9 @@ cd /go/src/github.com/grafana/grafana
 echo "current dir: $(pwd)"
 
 cd ..
-git clone -b ee_build --single-branch git@github.com:grafana/grafana-enterprise.git --depth 10
+git clone -b master --single-branch git@github.com:grafana/grafana-enterprise.git --depth 10
 cd grafana-enterprise
-git checkout 7fbae9c1be3467c4a39cf6ad85278a6896ceb49f
+#git checkout 7fbae9c1be3467c4a39cf6ad85278a6896ceb49f
 ./build.sh
 
 cd ../grafana