[Feature Request]: Generate XML schema for pipelines and workflows

### What would you like to happen?

It should be possible to generate XML schemas for Hop pipelines and workflows.
We have the rather simple metadata of pipelines and workflows.
The real issue is determining which elements the transforms and actions need.
I think it's possible to use the `@HopMetadataProperty` annotations to generate the `` entries.

### Issue Priority

Priority: 3

### Issue Component

Component: API

Start by examining Hop's pipeline and workflow metadata and the @HopMetadataProperty annotations mentioned in the issue. Determine how transform and action elements would map into XML schema entries. Done means generating usable XML schemas that include the required elements for pipelines and workflows.

Written by the indexing model from the issue text.