Plugins: Add validation stage to plugin loader pipeline (#73053)

* first pass

* change validation signature

* err tracking

* fix

* undo golden

* 1 more

* fix

* adjust doc

* add test helper

* fix linter

pkg/plugins/manager/loader/angular/angularinspector/angularinspector.go

@@ -73,6 +73,6 @@ func NewDefaultStaticDetectorsProvider() angulardetector.DetectorsProvider {
 
 // NewStaticInspector returns the default Inspector, which is a PatternsListInspector that only uses the
 // static (hardcoded) angular detection patterns.
-func NewStaticInspector() (Inspector, error) {
-	return &PatternsListInspector{DetectorsProvider: NewDefaultStaticDetectorsProvider()}, nil
+func NewStaticInspector() Inspector {
+	return &PatternsListInspector{DetectorsProvider: NewDefaultStaticDetectorsProvider()}
 }