Display image size for multiarch container images (#23821)

Fixes #23771

Changes the display of different architectures for multiarch images to
show the image size:

![grafik](https://user-images.githubusercontent.com/1666336/228781477-cc76c4d1-4728-434f-8a27-fc008790d924.png)

modules/packages/container/metadata.go

@@ -62,7 +62,13 @@ type Metadata struct {
 	DocumentationURL string            `json:"documentation_url,omitempty"`
 	Labels           map[string]string `json:"labels,omitempty"`
 	ImageLayers      []string          `json:"layer_creation,omitempty"`
-	MultiArch        map[string]string `json:"multiarch,omitempty"`
+	Manifests        []*Manifest       `json:"manifests,omitempty"`
+}
+
+type Manifest struct {
+	Platform string `json:"platform"`
+	Digest   string `json:"digest"`
+	Size     int64  `json:"size"`
 }
 
 // ParseImageConfig parses the metadata of an image config

modules/packages/container/metadata_test.go

@@ -46,7 +46,7 @@ func TestParseImageConfig(t *testing.T) {
 		},
 		metadata.Labels,
 	)
-	assert.Empty(t, metadata.MultiArch)
+	assert.Empty(t, metadata.Manifests)
 
 	configHelm := `{"description":"` + description + `", "home": "` + projectURL + `", "sources": ["` + repositoryURL + `"], "maintainers":[{"name":"` + author + `"}]}`