Plugins: Core plugins register via backend factory provider (#43171)

* refactoring store interface and init flow

* fix import

* fix linter

* refactor resource calling

* load with class

* re-order args

* fix tests

* fix linter

* remove old creator

* add custom config struct

* fix some tests

* cleanup

* fix

* tackle plugins

* fix linter

* refactor and fix test

* add connect failure error

* add fix for azure, cloud monitoring and test data

* restructure

* remove unused err

* add fake tracer for test

* fix grafana ds plugin

pkg/tsdb/mssql/mssql.go

@@ -17,8 +17,6 @@ import (
 	"github.com/grafana/grafana-plugin-sdk-go/data"
 	"github.com/grafana/grafana-plugin-sdk-go/data/sqlutil"
 	"github.com/grafana/grafana/pkg/infra/log"
-	"github.com/grafana/grafana/pkg/plugins"
-	"github.com/grafana/grafana/pkg/plugins/backendplugin/coreplugin"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/tsdb/sqleng"
 	"github.com/grafana/grafana/pkg/util"
@@ -26,25 +24,14 @@ import (
 
 var logger = log.New("tsdb.mssql")
 
-const pluginID = "mssql"
-
 type Service struct {
 	im instancemgmt.InstanceManager
 }
 
-func ProvideService(cfg *setting.Cfg, pluginStore plugins.Store) (*Service, error) {
-	s := &Service{
+func ProvideService(cfg *setting.Cfg) *Service {
+	return &Service{
 		im: datasource.NewInstanceManager(newInstanceSettings(cfg)),
 	}
-	factory := coreplugin.New(backend.ServeOpts{
-		QueryDataHandler: s,
-	})
-
-	resolver := plugins.CoreDataSourcePathResolver(cfg, pluginID)
-	if err := pluginStore.AddWithFactory(context.Background(), pluginID, factory, resolver); err != nil {
-		logger.Error("Failed to register plugin", "error", err)
-	}
-	return s, nil
 }
 
 func (s *Service) getDataSourceHandler(pluginCtx backend.PluginContext) (*sqleng.DataSourceHandler, error) {