Clean up Alaska NGA-Sub bias corrected GMMs

• Remove original bias correction
• Rename *_BIAS_CORR_NEW to *_ADJUSTED consistent with other, similarly 'adjusted' GMMs.

added 2023 GMM labels

assigned to @jaltekruse

mentioned in issue ghsc/nshmp/nshms/nshm-alaska#33 (closed)

The PGA reference calculation for AG20, KBCG20, and PSBAH20 all apply the Alaska bias adjustment for the target period and not for PGA. i.e.:

pgaRef = calcMean(coeffsPGA, coeffAkBias, ...)
mu = calcMean(coeffs, coeffAkBias, ...)

@pmpowers - Should we be using the PGA bias correction in the pgaRef calc? (coeffAkBiasPGA and coeffAkBias)

either have 1) a separate coeffAkBiasPGA coefficients object or 2) within coeffAkBias have correction and correctionPGA and use the appropriate adjustment in the reference calc. The latter seems simpler.

mentioned in merge request !409 (merged)

changed milestone to %Finalize 2023 NSHM and ongoing GMM work

marked the checklist item Remove original bias correction as completed

marked the checklist item Rename *_BIAS_CORR_NEW to *_ADJUSTED consistent with other, similarly 'adjusted' GMMs. as completed

PGA bias correction is now used to calculate PGAref

mentioned in commit f3735b90

closed with merge request !409 (merged)

Refactor NGA-Sub implementations to use 'data adjusted' instead of 'bias corrected'

reopened