Merge branch 'prvi-legacy-gmms' into 'main'

...s/earthquake/nshmp/gmm/CampbellBozorgnia_2003_Alaska.java

src/main/java/gov/usgs/earthquake/nshmp/gmm/CombinedGmm.java

src/main/java/gov/usgs/earthquake/nshmp/gmm/Gmm.java

...ov/usgs/earthquake/nshmp/gmm/MotazedianAtkinson_2003.java

...n/java/gov/usgs/earthquake/nshmp/gmm/SadighEtAl_1997.java

src/main/resources/gmm/coeffs/MotazedianAtkinson03.csv

src/test/java/gov/usgs/earthquake/nshmp/gmm/SEA99_test.java

src/test/resources/gmm/sea99-results.csv