Add Pipeline Support to MOJO

[exalate-issue-sync]

Add the ability for pre-processing data preparation steps to be supported by the MOJO. We should start with adding the H2OAssembly functionality into the MOJO pipeline first: [https://github.com/h2oai/h2o-3/blob/master/h2o-genmodel/src/main/java/hex/genmodel/GenMunger.java#L55|https://github.com/h2oai/h2o-3/blob/master/h2o-genmodel/src/main/java/hex/genmodel/GenMunger.java#L55|smart-link]

The pipeline MOJO should be able to return either the prepared dataset or the predictions.

[h2o-ops]

JIRA Issue Details

Jira Issue: PUBDEV-8793
Assignee: Marek Novotny
Reporter: Megan Kurka
State: In Progress
Fix Version: 3.42.0.1
Attachments: N/A
Development PRs: Available

[h2o-ops]

Linked PRs from JIRA

#6661