Watch and compare route before re-invoking fetch() in ResourceDetail

[rak-phillip]

Summary

This resolves an issue that was preventing the detail page from rendering. #12237 introduced a change that would prevent errors from being thrown if fetch() was invoked against a route without any keys in its query - a use case that was required for navigating between tabs in edit views.

This fix attempts to address a change in timing between route watchers and component unmounting by slightly modifying the approach taken in #12237 by watching the route and only allowing fetch() to re-invoke if the route hasn't changed. The differences observed appear to be related to:

• Vue2: Component unmounts before the route watcher invokes
• Vue3: Watcher triggers before the component unmounts, potentially raising unhandled exceptions during navigation between pages & tabs

Fixes #12267
Fixes #12275

Occurred changes and/or fixed issues

• watch $route instead of $route.query in ResourceDetail
• assert that $route.name hasn't changed before invoking fetch()

Areas or cases that should be tested

This modifies fetch() behavior for all edit components. Navigation between edit pages and tabs needs to be tested.

Areas which could experience regressions

Navigation and data fetching for edit components.

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