Use mixin for new dropdown style

What does this MR do?

Replace individual chunks for the new dropdown style by a mixin.

This is a followup of

• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13106
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13183
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13184

This also fixes the top margin for the affected dropdowns as in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13183.

Why was this MR needed?

Too much duplicate code.

What are the relevant issue numbers?

#28921 (moved), #35424 (closed)

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13183#note_36442062

changed the description

This should be merged after https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13193 (which introduces the mixin)

added blocked label

mentioned in merge request !13276 (merged)

changed the description

added 71 commits

• e0c71c2c...2f05a6a4 - 68 commits from branch master
• 9ad744b1 - Use dropdown mixin in header
• 02cd9b12 - Use dropdown mixin on cycle analytics page
• 05fc447f - Use dropdown mixin on repositorys page

Compare with previous version

@annabeldunstone Can you please review?

@cperessini This refactoring should fix the top margin of the project page dropdowns (and leave cycle analytics and header unchanged). So please have a quick look, too.

removed blocked label

assigned to @annabeldunstone

mentioned in merge request !13253 (merged)

mentioned in merge request !13128 (merged)

LGTM! Thanks @winh

approved this merge request

merged

mentioned in commit 00a02d14

@winh the cycle analytics dropdown looks good on master. What should I look for in the project page? I forget

@cperessini These are the affected dropdowns on the project page: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13193 Does that help?

@winh oh, I'm just supposed to check that the dropdowns from before still look good? They do

@cperessini Thank you for checking!