API proxy: add a stress test case

[jamestranovich-noaa]

Description

We want to add a stress test (or two!) to the API proxy designed specifically to provoke a worst-case alert geometry scenario for the API interop layer. In a real world example we observed recently, we had an alert spanning 16 forecast zones, with each zone having its own complex geographic shape. The geographic query and resulting point collection (over 10M of responses from the database) exhausted all memory on the API interop layer.

This stress test can then be used to measure improvements to the API interop layer -- how fast do we respond with that query? How much memory do we take up? Are our optimizations for this kind of query working?

CC @eric-gade

Acceptance criteria

• A stress test (or two) has been added to the API proxy
• We can "measure" the API interop layer response to the above stress test(s)