Add API support for looking up a user by username

Needed to support Huboard

mentioned in merge request !681 (closed)

Reassigned to @dzaporozhets

mentioned in issue #4105 (closed)

@stanhu maybe document this?

Added ~13884 label

Added 1 commit:

• 754e6bac - Add documentation

Added 178 commits:

• 754e6bac...be52c5d2 - 176 commits from branch gitlab-org:master
• fca1bb6d - Add API support for looking up a user by username
• 75b4e571 - Add documentation

Done!

Added 1 commit:

• 9622e174 - Add documentation for username API search

Reassigned to @stanhu

Added 76 commits:

• 9622e174...1cf45407 - 75 commits from branch gitlab-org:master
• 62a4eae4 - Add API support for looking up a user by username

Added 43 commits:

• 62a4eae4...188c13b7 - 42 commits from branch gitlab-org:master
• 6d7ed8c9 - Add API support for looking up a user by username

Added 1 commit:

• 8b442e06 - Add API support for looking up a user by username

Added 90 commits:

• 8b442e06...1a23af48 - 89 commits from branch gitlab-org:master
• 5a8c65b5 - Add API support for looking up a user by username

Reassigned to @dzaporozhets

@stanhu thank you ♥️

Milestone changed to 8.4

Status changed to merged

mentioned in commit 92bc7038

mentioned in issue #10421 (moved)

mentioned in commit bca874df

mentioned in commit a39f8463

mentioned in commit 6efe95dd

mentioned in commit 00740f73

mentioned in commit dc54c570

mentioned in commit 5e518c4f

mentioned in commit 61a81a3a

mentioned in commit 6facba91

mentioned in commit nolith/gitlab-ce@28b4d18f

mentioned in commit nolith/gitlab-ce@fa2ec0c3

mentioned in issue gitlab#4155