Enhancement: GBM monotone constraints for Poisson, Gamma families

[exalate-issue-sync]

Currently GBM monotone constraints exist for gaussian, bernoulli and tweedie (for power strictly between 1 and 2) families only. Extending this functionality to include Poisson and Gamma will be useful in financial services applications where regulation and/or client expectation dictates monotonic behaviour in response to certain factors

Previously raised by another user on h2ostream: [Poisson/Gamma GBM with monotonicity|https://groups.google.com/g/h2ostream/c/BEwC2iVZvgY?pli=1]

[h2o-ops]

JIRA Issue Details

Jira Issue: PUBDEV-8891
Assignee: New H2O Bugs
Reporter: N/A
State: Open
Fix Version: N/A
Attachments: N/A
Development PRs: N/A

[Alternikaner]

Extension/completion of #14868
Mailing list discussion: https://groups.google.com/g/h2ostream/c/BEwC2iVZvgY