Add live-coverage testing for FBFM40 seasonal fuels

[lindsaywiard]

Add real, end-to-end test coverage in the api for FBFM40 seasonal requests against a domain with known LFPS coverage, plus a check in Griddle that fails when LANDFIRE moves seasonal fuels past our configured version.

API

• Add a way to load a known-covered domain into test data, and a fixture for it.
• Split FBFM40's documented examples into ones that need LFPS coverage and ones that don't.
• Add a test that discovers whatever season is currently live in LFPS and posts a real request against the covered domain.

Griddle

• Add a test that fails (not skips) once our configured seasonal version is no longer live in LFPS's catalog, so a stale config shows up as a red build.