initial implementation of Gomez 2022. test results are unverified

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

src/main/java/gov/usgs/earthquake/nshmp/gmm/Gomez_2022.java

src/main/resources/gmm/coeffs/Gomez2022.csv

.../java/gov/usgs/earthquake/nshmp/gmm/Gomez_2022_tests.java

src/test/resources/gmm/gomez22-inputs.csv

src/test/resources/gmm/gomez22-results.csv