Merge branch 'add-prvi-test-sites' into 'main'

etc/nshm/sites-ciapr.csv

etc/nshm/sites-ciapr.geojson

etc/nshm/sites-nrc.csv

etc/nshm/sites-nrc.geojson

etc/nshm/sites-nshmp.csv

etc/nshm/sites-nshmp.geojson

etc/nshm/sites-prvi.csv

etc/nshm/sites-prvi.geojson

src/main/java/gov/usgs/earthquake/nshmp/site/NshmpSite.java

...n/java/gov/usgs/earthquake/nshmp/site/NshmpSiteFiles.java

...t/java/gov/usgs/earthquake/nshmp/site/NshmpSiteTests.java