Enable Grafana extensions at build time. (#11752)

* extensions: import and build

* bus: use predefined error

* enterprise: build script for enterprise packages

* poc: auto registering services and dependency injection

(cherry picked from commit b5b1ef875f905473af41e49f8071cb9028edc845)

* poc: backend services registry progress

(cherry picked from commit 97be69725881241bfbf1e7adf0e66801d6b0af3d)

* poc: minor update

(cherry picked from commit 03d7a6888b81403f458b94305792e075568f0794)

* ioc: introduce manuel ioc

* enterprise: adds setting for enterprise

* build: test and build specific ee commit

* cleanup: test testing code

* removes example hello service

pkg/services/sqlstore/sqlstore.go

@@ -77,7 +77,7 @@ func EnsureAdminUser() {
 	log.Info("Created default admin user: %v", setting.AdminUser)
 }
 
-func NewEngine() {
+func NewEngine() *xorm.Engine {
 	x, err := getEngine()
 
 	if err != nil {
@@ -91,6 +91,8 @@ func NewEngine() {
 		sqlog.Error("Fail to initialize orm engine", "error", err)
 		os.Exit(1)
 	}
+
+	return x
 }
 
 func SetEngine(engine *xorm.Engine) (err error) {