Add 'from commit' information to cherry-picked commits

Store the original commit in the commit message, solving #32348 (closed).

The original commit(s) are appended to the commit message. There are two possible cases: cherry-pick a regular commit, and a merge one.

In the case of a regular commit, the format of git cherry-pick -x is used:

(cherry picked from commit cafebabe)

In the case of a merge commit, the same message is appended, plus a listing of the commits between the merge commit and the start branch, in the git interactive rebase format:

(cherry picked from commit deadbeef)

5ca1ab1e Make more scalable
ca11ab1e Now it's callable