code sign safe updates: add clonefile and link metrics

While I am here, also renamed `Mac.App.CodeSignCloneCreationTime` to
`Mac.AppCodeSignCloneCreationTime` to align with the style of the other
App metrics.

Bug: 343931233
Change-Id: Ie9988f9476849927333b1ff7289c5383ead7481f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5615750


Commit-Queue: Tom Burgin <bur@google.com>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1312929}