Make source files refering to directories work

aspect_rules_js seems to use this to bring in source files belonging to
NPM packages. Let's generalize fileAndDependenciesCopier, so that it can
be used both for files and target action outputs.

Author: EdSchouten

pkg/model/analysis/file_properties_value.go

@@ -64,6 +64,9 @@ func (r *reposFilePropertiesResolver[TReference, TMetadata]) setCurrentRepo(name
 }
 
 func (r *reposFilePropertiesResolver[TReference, TMetadata]) OnDirectory(name path.Component) (path.GotDirectoryOrSymlink, error) {
+	if r.currentRepo != nil {
+		return r.currentRepo.OnDirectory(name)
+	}
 	if err := r.setCurrentRepo(name.String()); err != nil {
 		return nil, err
 	}
@@ -78,6 +81,9 @@ func (r *reposFilePropertiesResolver[TReference, TMetadata]) OnTerminal(name pat
 }
 
 func (r *reposFilePropertiesResolver[TReference, TMetadata]) OnUp() (path.ComponentWalker, error) {
+	if r.currentRepo != nil {
+		return r.currentRepo.OnUp()
+	}
 	return nil, errors.New("path escapes repositories directory")
 }