Add a check for allom_h2cd when allom_dmode=1

[glemieux]

Discussed in #1308

^{Originally posted by glemieux January 10, 2025}
Reviewing the CrownDepth subroutine and the default parameter file, I'm assuming that the allom_h2cd1 value should be between 0 and 1 such that the crown depth can't exceed the cohort height. I don't see a check in PRTCheckParams however.