Add data ingestion warnings to Dashboards

[gggritso]

Problem Statement

We have a lot of customers who run out of quota, or run into spikes, or otherwise see data that's missing. On Dashboards, this often results in mysterious or confusing behaviour. One example: #80529 but just generally, it's useful to show people when their numbers look weird because of billing problems. We do this in some parts of the app, but not others.

Solution Brainstorm

• add a warning bar to the top of the page, pointing out where data is missing
• add information about spikes, quota errors, ingestion delays, etc.

Product Area

Dashboards

[getsantry]

Routing to @getsentry/product-owners-dashboards for triage ⏲️

[bcoe]

@gggritso I feel we should consider designing a prettier informational dialog for the top of Insights / Dashboards that:

• Looks better than the marketing pop-ups we slap on things today.
• Allows for more content than a generic warning bar (I'm imagining linking out to help articles, etc.)

Running lighthouse in inspector you get this nice little dialog while it runs, which I think we could take inspiration from: