Determine chart digest by manifest

Currently, whenever the chart is printed, the digest of the .tar.gz
content layer is printed as the digest. The manifest digest is important
for OCI purposes, particularly in pushing to a registry.

Resolves #8248.

Signed-off-by: Peter Engelbert <pmengelbert@gmail.com>

internal/experimental/registry/client.go

@@ -240,7 +240,7 @@ func (c *Client) PrintChartTable() error {
 // printCacheRefSummary prints out chart ref summary
 func (c *Client) printCacheRefSummary(r *CacheRefSummary) {
 	fmt.Fprintf(c.out, "ref:     %s\n", r.Name)
-	fmt.Fprintf(c.out, "digest:  %s\n", r.Digest.Hex())
+	fmt.Fprintf(c.out, "digest:  %s\n", r.Manifest.Digest.Hex())
 	fmt.Fprintf(c.out, "size:    %s\n", byteCountBinary(r.Size))
 	fmt.Fprintf(c.out, "name:    %s\n", r.Chart.Metadata.Name)
 	fmt.Fprintf(c.out, "version: %s\n", r.Chart.Metadata.Version)
@@ -257,7 +257,7 @@ func (c *Client) getChartTableRows() ([][]interface{}, error) {
 		refsMap[r.Name] = map[string]string{
 			"name":    r.Chart.Metadata.Name,
 			"version": r.Chart.Metadata.Version,
-			"digest":  shortDigest(r.Digest.Hex()),
+			"digest":  shortDigest(r.Manifest.Digest.Hex()),
 			"size":    byteCountBinary(r.Size),
 			"created": timeAgo(r.CreatedAt),
 		}