Disable breadcrumbs outside of pages, SnippetViewSet, and custom ModelViewSet

[laymonage]

Undo the breadcrumbs unintentionally added in #10880 and intentionally added in #10884 until we can implement the designs that are better suited for various use cases throughout the admin.

To re-enable in the future, revert the first two commits from this PR.

I also added a commit to disable the minimap if there are no panel anchors found, to prevent the minimap from rendering on the ModelViewSet views as they currently don't use panels. When they do support panels after #10830, the minimap should be rendered automatically.

Please check the following:

• Do the tests still pass?¹
• Does the code comply with the style guide?
  • Run make lint from the Wagtail root.
• For Python changes: Have you added tests to cover the new/fixed behaviour?

Please describe additional details for testing this change.

Use my bakerydemo branch: https://github.com/laymonage/bakerydemo/tree/country-modelviewset

And see that:

• The views for County of Origin still have breadcrumbs (and status side panel)
• The views for all snippets still have breadcrumbs
• The following views do not have breadcrumbs at all:
  • Workflows
  • Workflow tasks
  • Users
  • Groups
  • Sites
  • Locales
  • Collections

Footnotes

1. Development Testing ↩

[squash-labs]

Manage this branch in Squash

Test this branch here: https://laymonagedisable-unintentional-b5t6i.squash.io

[thibaudcolas]

Thank you @laymonage! Looking good in Safari & Chrome.