Fix intermittently failed click in dropdown in QA

What does this MR do?

Fixes an intermittent failure in which the dropdown toggle button is clicked seemingly before the JS toggle code is bound, so it fails in the next line where we try to click a dropdown item.

Are there points in the code the reviewer needs to double check?

The wait method modification is the same as in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/4270, but I assume merging should not be a problem.

Why was this MR needed?

Failures:

  1) GitLab Geo replication users pushes code to the primary node
     Failure/Error:
       project = Factory::Resource::Project.fabricate! do |project|
         project.name = 'geo-project'
         project.description = 'Geo test project'
       end
     
     Capybara::ElementNotFound:
       Unable to find visible css "li[data-value='new-project']" within #<Capybara::Node::Element tag="div" path="/html/body/div[2]/div[2]/div[3]/div/div[2]/div[1]/div/div[2]">
     # ./qa/page/group/show.rb:38:in `block in go_to_new_project'
     # ./qa/page/group/show.rb:36:in `go_to_new_project'
     # ./qa/factory/resource/project.rb:23:in `block in fabricate!'
     # ./qa/scenario/actable.rb:5:in `instance_exec'
     # ./qa/scenario/actable.rb:5:in `act'
     # ./qa/scenario/actable.rb:18:in `act'
     # ./qa/factory/resource/project.rb:23:in `fabricate!'
     # ./qa/factory/base.rb:23:in `block in fabricate!'
     # ./qa/factory/base.rb:16:in `tap'
     # ./qa/factory/base.rb:16:in `fabricate!'
     # ./qa/specs/features/ee/geo/replication_spec.rb:7:in `block (3 levels) in <module:QA>'
     # ./qa/runtime/browser.rb:105:in `perform'
     # ./qa/runtime/browser.rb:27:in `visit'
     # ./qa/runtime/browser.rb:31:in `visit'
     # ./qa/specs/features/ee/geo/replication_spec.rb:4:in `block (2 levels) in <module:QA>'
     # ./qa/specs/runner.rb:22:in `perform'
     # ./qa/scenario/template.rb:7:in `block in perform'
     # ./qa/scenario/template.rb:5:in `tap'
     # ./qa/scenario/template.rb:5:in `perform'
     # ./qa/ee/scenario/test/geo.rb:27:in `perform'
     # ./qa/scenario/template.rb:7:in `block in perform'
     # ./qa/scenario/template.rb:5:in `tap'
     # ./qa/scenario/template.rb:5:in `perform'
     # ./qa/scenario/bootable.rb:26:in `launch!'

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• If paid feature, have we considered GitLab.com plan and how it works for groups and is there a design for promoting it to users who aren't on the correct plan
• End-to-end tests pass (package-qa manual pipeline job)

What are the relevant issue numbers?