repository: move Blob, Blobs and PackedBlob to pack package

This removes them from the public interface. The latter now only
provides the PackBlob interface, without being bound to the type used
internally by the pack package.

internal/repository/checker_test.go

@@ -21,7 +21,7 @@ import (
 var checkerTestData = filepath.Join("..", "checker", "testdata", "checker-test-repo.tar.gz")
 
 func testWrapCheckPack(ctx context.Context, t *testing.T, repo *Repository,
-	packID restic.ID, blobs []restic.Blob, size int64,
+	packID restic.ID, blobs pack.Blobs, size int64,
 ) error {
 	t.Helper()
 	bufRd := bufio.NewReaderSize(nil, maxStreamBufferSize)
@@ -46,7 +46,7 @@ func TestGapInBlobs(t *testing.T) {
 	_, ok := repoPacks[packID]
 	rtest.Assert(t, ok, "expected pack 19a731a515618ec8b75fc0ff3b887d8feb83aef1001c9899f6702761142ed068")
 
-	blobs := []restic.Blob{}
+	blobs := pack.Blobs{}
 	pb := <-repo.listPacksFromIndex(context.TODO(), restic.NewIDSet(packID))
 	blobs = append(blobs, pb.Blobs...)