Single module/assembly for both source and sink connectors

# What is currently missing?

There's not much benefit to separating the source and sink connectors into different jars:
- it complicates the structure of the repo and the build,
- we're currently generating a full 94MB assembly for each connector even though they have a majority of duplicated dependencies (99% shared DNA!)

# How could this be improved?

Consider a single module (or module-less) maven project with the classes separated by package instead of into separate jars and a single assembly

# Is this a feature you would work on yourself?

* [ ] I plan to open a pull request for this feature

Start by inspecting the Maven project structure and the separate source and sink connector modules, packages, and assembly configuration. Determine how the duplicated dependencies and 94MB assemblies are produced; done means the connectors share one module or project layout and one assembly without losing either connector.

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