Plugins: Ignore symlinked folders when verifying plugin signature (#34434) (#35719)

* add check + test

* fix test

* add manifest

* fix linter

* add nolint

* separate err cond checks

* only collect relevant plugin files

* skip symlinks

* refactor

* add missing test files + enable scanning Chromium.app/

* remove test since case already covered

* remove unnecessary changes from before

* refactor

* remove comment

(cherry picked from commit 303352a89b)

Co-authored-by: Will Browne <wbrowne@users.noreply.github.com>

pkg/plugins/models.go

@@ -71,7 +71,6 @@ type PluginBase struct {
 	PluginDir       string              `json:"-"`
 	DefaultNavUrl   string              `json:"-"`
 	IsCorePlugin    bool                `json:"-"`
-	Files           []string            `json:"-"`
 	SignatureType   PluginSignatureType `json:"-"`
 	SignatureOrg    string              `json:"-"`