Introduce TSDB service (#31520)

* Introduce TSDB service

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Co-authored-by: Erik Sundell <erik.sundell87@gmail.com>
Co-authored-by: Will Browne <will.browne@grafana.com>
Co-authored-by: Torkel Ödegaard <torkel@grafana.org>
Co-authored-by: Will Browne <wbrowne@users.noreply.github.com>
Co-authored-by: Zoltán Bedi <zoltan.bedi@gmail.com>

pkg/api/frontendsettings.go

@@ -5,6 +5,7 @@ import (
 	"strconv"
 
 	"github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/plugins/manager"
 
 	"github.com/grafana/grafana/pkg/components/simplejson"
 	"github.com/grafana/grafana/pkg/util"
@@ -109,12 +110,12 @@ func (hs *HTTPServer) getFSDataSources(c *models.ReqContext, enabledPlugins *plu
 
 	// add data sources that are built in (meaning they are not added via data sources page, nor have any entry in
 	// the datasource table)
-	for _, ds := range plugins.DataSources {
+	for _, ds := range manager.DataSources {
 		if ds.BuiltIn {
 			dataSources[ds.Name] = map[string]interface{}{
 				"type": ds.Type,
 				"name": ds.Name,
-				"meta": plugins.DataSources[ds.Id],
+				"meta": manager.DataSources[ds.Id],
 			}
 		}
 	}
@@ -124,7 +125,7 @@ func (hs *HTTPServer) getFSDataSources(c *models.ReqContext, enabledPlugins *plu
 
 // getFrontendSettingsMap returns a json object with all the settings needed for front end initialisation.
 func (hs *HTTPServer) getFrontendSettingsMap(c *models.ReqContext) (map[string]interface{}, error) {
-	enabledPlugins, err := plugins.GetEnabledPlugins(c.OrgId)
+	enabledPlugins, err := hs.PluginManager.GetEnabledPlugins(c.OrgId)
 	if err != nil {
 		return nil, err
 	}