Adjust framework to be multi-lingual and modular

[incident-recipient]

A python and typescript implementation of PDSL is going to be necessary. At a minimum the proto files and the gherkin parser need to be broken out into their own project.

In addition to this we should probably break the JUnit4 and JUnit5 implementations into their own repository as well.

This will produce breaking changes. While we're at it we should do other housekeeping tasks.

One would be to replace providers with suppliers instead. This will remove the need for a library and allow us to use a native (and more flexible) feature in the standard library instead.

[incident-recipient]

Since the JVM is a hard requirement to use ANTLR, a contributor suggested we use a library that shares memory between the JVM and python. A pilot project worked successfully, so there doesn't appear to be a strong need to develop a python specific implementation of PDSL.