Plugins: Add /meta and /metas APIs to plugins app (#113775)

* add /meta and /metas APIs

* wrapped storage route

* format file

* fix switch statement lint issue

* fix plugininstaller test

---------

Co-authored-by: Todd Treece <todd.treece@grafana.com>

apps/plugins/pkg/app/meta/provider.go

@@ -0,0 +1,27 @@
+package meta
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	pluginsv0alpha1 "github.com/grafana/grafana/apps/plugins/pkg/apis/plugins/v0alpha1"
+)
+
+var (
+	ErrMetaNotFound = errors.New("not found")
+)
+
+// Result contains plugin metadata along with its recommended TTL.
+type Result struct {
+	Meta pluginsv0alpha1.PluginMetaJSONData
+	TTL  time.Duration
+}
+
+// Provider is used for retrieving plugin metadata.
+type Provider interface {
+	// GetMeta retrieves plugin metadata for the given plugin ID and version.
+	// Returns the Result containing the PluginMetaJSONData and its recommended TTL.
+	// If the plugin is not found, returns ErrMetaNotFound.
+	GetMeta(ctx context.Context, pluginID, version string) (*Result, error)
+}