api: Validate dashboards on save via coremodels, behind feature toggle (#48252)

* Add coremodelValidation feature flag

* coremodels: use stubs when feature flag is off

* api: validate dashboards on save

* Need pointer receiver for FeatureManager

* Update dashboard Go model

* Align doc comments

* Include CoremodelRegistry in test

* Wedge coremodel in on all test cases, ugh

* Ugh fix comment again

* Update pkg/framework/coremodel/staticregistry/provide.go

Co-authored-by: Artur Wierzbicki <wierzbicki.artur.94@gmail.com>

* Update Thema (and its deps) for better errs

* omg whitespace

Co-authored-by: Artur Wierzbicki <wierzbicki.artur.94@gmail.com>

pkg/framework/coremodel/registry.go

@@ -76,3 +76,12 @@ func (r *Registry) addModels(models []Interface) error {
 
 	return nil
 }
+
+// Get retrieves a coremodel with the given string identifier. nil, false
+// is returned if no such coremodel exists.
+func (r *Registry) Get(name string) (cm Interface, has bool) {
+	r.lock.RLock()
+	cm, has = r.modelIdx[name]
+	r.lock.RUnlock()
+	return
+}

pkg/framework/coremodel/staticregistry/provide.go

@@ -11,7 +11,9 @@ import (
 func ProvideRegistry(
 	dashboard *dashboard.Coremodel,
 ) (*coremodel.Registry, error) {
-	return coremodel.NewRegistry(
+	cmlist := []coremodel.Interface{
 		dashboard,
-	)
+	}
+
+	return coremodel.NewRegistry(cmlist...)
 }