Port of experimental-breadcrumbs to EE

See merge request !2314

Speed up issue counting for a project

See merge request !2310

Fix approvals request throwing 400 in IE 11

Closes #1874

See merge request !2306

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CE upstream - Wednesday

See merge request !2293

Resolve "More actions dropdown hidden by end of diff"

Closes #33861

See merge request !12380

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This runs a slightly slower query to get the issue and MR counts in the
navigation, but caches by user type (can see all / none confidential issues) for
two minutes.

When we are filtering by a single project, and the current user has access to
see confidential issues on that project, we don't need to filter by
confidentiality at all - just as if the user were an admin.

The filter by confidentiality often picks a non-optimal query plan: for
instance, AND-ing the results of all issues in the project (a relatively small
set), and all issues in the states requested (a huge set), rather than just
starting small and winnowing further.

Only verifies top position after the request has finished to account for errors

See merge request !12559

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