Add encoding/decoding performance test baselines

[1ec5]

Added a performance test of encoding and decoding the notoriously complex boundary of the Navajo Nation from the 2020 U.S. Census.

As a proof of concept (but mostly so it’s easy to retrieve later), I also added baselines from v1.2.0 on my local machine for comparison with the current state of the main branch. The existing performance tests, which repeatedly encode and decode a very simple feature collection, have gotten slightly worse (within 10% worse) as of main, but the new tests, which encode and decode the very complex feature collection just once, has gotten slightly better (within 10% better). The exact figures aren’t very stable so it’s nothing more than a gut check of the significant changes that have recently gone into Turf’s GeoJSON support.

/cc @mapbox/navigation-ios