Edit blob button doesn't work on Blame page for signed in users without access to the repo

Bug introduced in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10233.

This section of code should be moved to the projects/blob/header partial to be available on both the Blob and Blame pages.

/cc @MadLittleMods

mentioned in issue #28899 (closed)

mentioned in commit 095cef1a

mentioned in merge request !10598 (merged)

mentioned in commit b4f0ecde

assigned to @MadLittleMods

closed via merge request !10598 (merged)

mentioned in commit a43b3dcf

mentioned in commit 40ce3819

mentioned in merge request !14785