Plugins: Refactor loader + finder to support multiple sourcing methods (#64735)

* it's cdn time

* tidy body closing

* auto signed

* fix close

* update log name

* remove comments

pkg/plugins/manager/sources/source_local_disk.go

@@ -0,0 +1,38 @@
+package sources
+
+import (
+	"context"
+
+	"github.com/grafana/grafana/pkg/plugins"
+)
+
+type LocalSource struct {
+	paths []string
+	class plugins.Class
+}
+
+func NewLocalSource(class plugins.Class, paths []string) *LocalSource {
+	return &LocalSource{
+		class: class,
+		paths: paths,
+	}
+}
+
+func (s *LocalSource) PluginClass(_ context.Context) plugins.Class {
+	return s.class
+}
+
+func (s *LocalSource) PluginURIs(_ context.Context) []string {
+	return s.paths
+}
+
+func (s *LocalSource) DefaultSignature(_ context.Context) (plugins.Signature, bool) {
+	switch s.class {
+	case plugins.Core:
+		return plugins.Signature{
+			Status: plugins.SignatureInternal,
+		}, true
+	default:
+		return plugins.Signature{}, false
+	}
+}