feat(sync): use regclient for sync extension (#2903)

* feat(sync): use regclient for sync extension

replaced containers/image package with regclient/regclient package

Signed-off-by: Eusebiu Petu <petu.eusebiu@gmail.com>

* fix(sync): fixed converting innner docker list mediatype

Signed-off-by: Eusebiu Petu <petu.eusebiu@gmail.com>

* feat(sync): added option to preserve digest

Signed-off-by: Eusebiu Petu <petu.eusebiu@gmail.com>

* fix(sync): added coverage and various fixes

Signed-off-by: Eusebiu Petu <petu.eusebiu@gmail.com>

* fix(metadb): fixed converting manifest list not setting platform and annotations

Signed-off-by: Eusebiu Petu <petu.eusebiu@gmail.com>

* fix(sync): remove read lock on storage, not used concurrently

Signed-off-by: Eusebiu Petu <petu.eusebiu@gmail.com>

* feat(sync): added cache for repo tags

Signed-off-by: Eusebiu Petu <petu.eusebiu@gmail.com>

* fix(sync): fixed Makefile
removed opengpg tag

Signed-off-by: Eusebiu Petu <petu.eusebiu@gmail.com>

* fix(sync): add test for on demand referrer

Signed-off-by: Eusebiu Petu <petu.eusebiu@gmail.com>

---------

Signed-off-by: Eusebiu Petu <petu.eusebiu@gmail.com>

pkg/storage/gc/gc.go

@@ -322,7 +322,7 @@ func (gc GarbageCollect) removeReferrer(repo string, index *ispec.Index, manifes
 	// cosign
 	tag, ok := getDescriptorTag(manifestDesc)
 	if ok {
-		if isCosignTag(tag) {
+		if zcommon.IsCosignTag(tag) {
 			subjectDigest := getSubjectFromCosignTag(tag)
 			referenced := isManifestReferencedInIndex(index, subjectDigest)
 
@@ -785,16 +785,6 @@ func getDescriptorTag(desc ispec.Descriptor) (string, bool) {
 	return tag, ok
 }
 
-// this function will check if tag is a cosign tag (signature or sbom).
-func isCosignTag(tag string) bool {
-	if strings.HasPrefix(tag, "sha256-") &&
-		(strings.HasSuffix(tag, cosignSignatureTagSuffix) || strings.HasSuffix(tag, SBOMTagSuffix)) {
-		return true
-	}
-
-	return false
-}
-
 /*
 	GCTaskGenerator takes all repositories found in the storage.imagestore
 

pkg/storage/storage.go

@@ -259,7 +259,7 @@ func CheckIsImageSignature(repoName string, manifestBlob []byte, reference strin
 		return true, CosignType, manifestContent.Subject.Digest, nil
 	}
 
-	if tag := reference; zcommon.IsCosignTag(reference) {
+	if tag := reference; zcommon.IsCosignSignature(reference) {
 		prefixLen := len("sha256-")
 		digestLen := 64
 		signedImageManifestDigestEncoded := tag[prefixLen : prefixLen+digestLen]