Move "Move issue" to sidebar - EE merge edition
EE merge edition of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13616
Also cherry-picked the following because it hasn't made it to EE
Edited by Coung Ngo
EE merge edition of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13616
Also cherry-picked the following because it hasn't made it to EE