This is still not functional, because it involves a LOT of changes to
the basic structure of the project. Some of the main changes can be seen
in the CHANGELOG.md file, if you're interested, but it boils down to
simplifying the logic of plugins (no more activation/deactivation
shenanigans), more robust typing and use of schemas (pydantic) to
avoid inconsistencies and user errors.
* Fixed Options for extra_params in UI
* Enhanced meta-programming for models
* Plugins can be imported from a python file if they're named
`senpy_<whatever>.py>` (no need for `.senpy` anymore!)
* Add docstings and tests to most plugins
* Read plugin description from the docstring
* Refactor code to get rid of unnecessary `.senpy`s
* Load models, plugins and utils into the main namespace (see __init__.py)
* Enhanced plugin development/experience with utils (easy_test, easy_serve)
* Fix bug in check_template that wouldn't check objects
* Make model defaults a private variable
* Add option to list loaded plugins in CLI
* Update docs
