Abbreviate the VC revision in vc-annotate's buffer name

* lisp/vc/vc-hooks.el (vc-use-short-revision): New variable.
(vc-short-revision): New function.

* lisp/vc/vc-annotate.el (vc-annotate-use-short-revision): New
option...
(vc-annotate): ... use it.

* lisp/vc/vc-git.el (vc-git--rev-parse): Consult
'vc-use-short-revision'.

* etc/NEWS: Announce this change (bug#67062).
1 job for master in 9 minutes and 44 seconds (queued for 3 minutes and 7 seconds)
Status Job ID Name Coverage
  Normal
failed #79005
test-lisp-vc-inotify

00:09:44

 
Name Stage Failure
failed
test-lisp-vc-inotify Normal
Uploading artifacts for failed job
Uploading artifacts...
WARNING: test-lisp-vc-inotify-ea4cbb3a/: no matching files. Ensure that the artifact path is relative to the working directory
ERROR: No files to upload
Uploading artifacts...
WARNING: test-lisp-vc-inotify-ea4cbb3a/junit-test-report.xml: no matching files. Ensure that the artifact path is relative to the working directory
ERROR: No files to upload
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1