Support priv/unpriv image extraction

Optionally add back privileged extraction which can be enabled with
LUET_PRIVILEGED_EXTRACT=true

Signed-off-by: Ettore Di Giacinto <mudler@sabayon.org>

vendor/github.com/moby/buildkit/client/llb/resolver.go

@@ -0,0 +1,26 @@
+package llb
+
+import (
+	"context"
+
+	digest "github.com/opencontainers/go-digest"
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+// WithMetaResolver adds a metadata resolver to an image
+func WithMetaResolver(mr ImageMetaResolver) ImageOption {
+	return imageOptionFunc(func(ii *ImageInfo) {
+		ii.metaResolver = mr
+	})
+}
+
+// ImageMetaResolver can resolve image config metadata from a reference
+type ImageMetaResolver interface {
+	ResolveImageConfig(ctx context.Context, ref string, opt ResolveImageConfigOpt) (digest.Digest, []byte, error)
+}
+
+type ResolveImageConfigOpt struct {
+	Platform    *specs.Platform
+	ResolveMode string
+	LogName     string
+}