Discussion tab including award emoji's on commits

For example it would be nice to be able to thumbs-up this commit: gitlab-com/www-gitlab-com@1400ab7c

Also when wanting to leave a comment, now you have to scroll all the way down.

proposal

adding discussion tab to commit view

Caveats

• Currently the award emoji is within the discussion tab for MR's.. we should move it out of the tabs and make it available even when viewing changes etc. This should be done in a separate issue imo. edit: created issue for this https://gitlab.com/gitlab-org/gitlab-ce/issues/25996
• In the MR discussion tab, we have focussed conversations pop-up that have been made within the diff view, we should have consistency with the discussion tab in the commits view as well. This makes the scope of this issue somewhat larger.

@victorwu this is imo part of the things that still need to happen to complete our consistency across our conversation functionality.

cc: @awhildy