Module refactor

[hellais]

As part of this PR based on top of oonirunv2-improvements branch I implement the new pattern for building microservices in the new ooni api.

The main things it achieves are the following:

• Switch to using hatch for dependency management instead of poetry
• Create a more robust directory structure for the project
• Implement a re-usable pattern for creating new services trying to minimize boilerplate to the extent possible
• Add basic Readme
• Promote new ooniapi to the top level directory tree

[hellais]

What's missing:

• Fixing the measurements module to work with the new pattern
• Come up with a better pattern for handling config settings so they are not shared in the common folder (this requires refactoring the common/utils though)
• Updating the CI/CD pipeline to use the new directory structure