distro/rhel85: tar-installer -> image-installer

Renamed tar-installer to image-installer.
This is a more appropriate name:
- It disassociates the image type from the "tar" image type. The two
  should not be perceived to be connected.
- It's more descriptive. The format of the payload (tar) isn't relevant
  to the purpose of the image type.

internal/distro/rhel85/distro.go

@@ -761,7 +761,7 @@ func newDistro(name, modulePlatformID, ostreeRef string) distro.Distro {
 		exports:   []string{"root-tar"},
 	}
 	tarInstallerImgTypeX86_64 := imageType{
-		name:     "tar-installer",
+		name:     "image-installer",
 		filename: "installer.iso",
 		mimeType: "application/x-iso9660-image",
 		packageSets: map[string]rpmmd.PackageSet{

internal/distro/rhel85/distro_test.go

@@ -104,8 +104,8 @@ func TestFilenameFromType(t *testing.T) {
 			},
 		},
 		{
-			name: "tar-installer",
-			args: args{"tar-installer"},
+			name: "image-installer",
+			args: args{"image-installer"},
 			want: wantResult{
 				filename: "installer.iso",
 				mimeType: "application/x-iso9660-image",
@@ -264,7 +264,7 @@ func TestImageType_Name(t *testing.T) {
 				"edge-container",
 				"edge-installer",
 				"tar",
-				"tar-installer",
+				"image-installer",
 			},
 		},
 		{
@@ -446,7 +446,7 @@ func TestArchitecture_ListImageTypes(t *testing.T) {
 				"edge-container",
 				"edge-installer",
 				"tar",
-				"tar-installer",
+				"image-installer",
 			},
 		},
 		{

internal/store/json.go

@@ -356,7 +356,7 @@ var imageTypeCompatMapping = map[string]string{
 	"edge-commit":         "edge-commit",
 	"edge-container":      "edge-container",
 	"edge-installer":      "edge-installer",
-	"tar-installer":       "tar-installer",
+	"image-installer":     "image-installer",
 	"test_type":           "test_type",         // used only in json_test.go
 	"test_type_invalid":   "test_type_invalid", // used only in json_test.go
 	"ec2":                 "ec2",