[k7/Monitoring] Make breadcrumbs more consistent

[spalger]

See the #25884 for more general information.

The breadcrumbs in Management look pretty good, but there are a number of cases where the breadcrumbs include things like tab names, don't change between different pages, or don't properly describe the current page. I've tried to set in and update the breadcrumb generation logic that exists but there are a lot of different things happening in one place and I'm not sure how to make the updates correctly. "Invalid" breadcrumbs are also used for navigation purposes in the functional tests, so rather than removing them and updating the functional tests in a way I don't understand I'd like to sit down with either @ycombinator or @chrisronline once they're back from vacation and figure out how to update things for k7.

[elasticmachine]

Pinging @elastic/kibana-monitoring