Link commit message history with files in merge requests

Description

It would be great to get the commit messages history related to any files in the Changes tab when reviewing code during a merge requests.

Proposal

In the same way it is possible to Hide whitespace changes, we could have a Show files commit history to quickly enabling or disabling it.
Maybe a per file button would be more suitable.

"feature proposal" gitlab-ce3079098 gitlab-ce2658854 gitlab-ce3412204