Dashboard failed error state

What does this MR do and why?

Adds a global dashboard error state to analytics dashboards.

This is for situations where the entire dashboard fails to load, (as opposed to individual dashboard panels, which already have their own error state).

Note that product analytics is an experimental feature behind a default-off feature flag.

Screenshots or screen recordings

Before	After
(forever loading state)

How to set up and validate locally

1. Follow these instructions to setup Product Analytics in GDK.
2. Onboard Product Analytics by setting up the feature at Project > Analytics > Analytics dashboards.
3. View the dashboard listing at Project > Analytics > Analytics dashboards.
4. Disable your network within devtools to simulate a network error
5. Click on a dashboard in the list to load it
6. Verify that the dashboard displays a new top level error message

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #418008 (closed)