Update Feed Warning View

Add information to the feed warning view. This is the modal pop-up that appears when we attempt to load a large earthquake feed (more than 2,000 events).

We would like to add:

• A subheader with the number of events that we are trying to load. Currently, you get the warning, but you don't have any idea how many events the interface is trying to load. If we could change the text to "The current selection includes {{ number of events }} earthquakes, this is more than your device may be able to display."
• Check if a search was performed before asking the user to "modify the search", only display this option if the current feed is a search.

*Update - e2e tests failed on this pipeline after merging