Add ValidateSelector to versioner interface and consume it

We can refactor furthermore by dropping the package methods, as now we
can consume a versioner in all places that requires it

pkg/versioner/interface.go

@@ -22,4 +22,6 @@ type Versioner interface {
 	Sanitize(string) string
 	Validate(string) error
 	Sort([]string) []string
+
+	ValidateSelector(version string, selector string) bool
 }