Plugins: Add synchronous CDN plugin loader (#99096)

* WIP

* Run plugin validations and validation steps sequentially if feature is off

* Remove dependency between sources.Service and pluginscdn.Service

* lint

* Parallelize validation only if class is CDN

* re-generate feature toggles

* remove waitgroup usage

* PR review: Add loader concurrency limit setting

* re-generate feature toggles

* pr review feedback

* fix const name

* Skip module.js validation for cdn plugins

* do not run validation steps in parallel

* lint

* reduce diff

* re-generate feature toggles

* lint

* pr review feedback

* remove leftover config.PluginManagementCfg from sources.Service

pkg/services/pluginsintegration/loader/loader.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/grafana/grafana/pkg/plugins"
+	"github.com/grafana/grafana/pkg/plugins/config"
 	pluginsLoader "github.com/grafana/grafana/pkg/plugins/manager/loader"
 	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/bootstrap"
 	"github.com/grafana/grafana/pkg/plugins/manager/pipeline/discovery"
@@ -19,11 +20,13 @@ type Loader struct {
 	loader *pluginsLoader.Loader
 }
 
-func ProvideService(discovery discovery.Discoverer, bootstrap bootstrap.Bootstrapper, validation validation.Validator,
+func ProvideService(
+	cfg *config.PluginManagementCfg,
+	discovery discovery.Discoverer, bootstrap bootstrap.Bootstrapper, validation validation.Validator,
 	initializer initialization.Initializer, termination termination.Terminator, errorTracker pluginerrs.ErrorTracker,
 ) *Loader {
 	return &Loader{
-		loader: pluginsLoader.New(discovery, bootstrap, validation, initializer, termination, errorTracker),
+		loader: pluginsLoader.New(cfg, discovery, bootstrap, validation, initializer, termination, errorTracker),
 	}
 }