Show realtime ingestion lag if > X seconds

[corywatilo]

Is your feature request related to a problem?

When using Event Explorer to verify events are getting ingested, it can be tricky if there's an event processing lag. This also leads to more support requests when customers expect their data to be there but it isn't.

Describe the solution you'd like

If ingestion lag is greater than, let's say 20 seconds, we should show a small line of text (maybe across from the page title) that says something like:

Current event processing time: 3 mins

[kiran-4444]

Hey, can I work on this? I know that this isn't a good-first-issue but with few pointers I'm sure I can work on this.