Reproducible development environments with VSCode devcontainers

If devcontainer is set to "y" project uses the VSCode devcontainer specification to create a reproducible development environment. The devcontainer is defined in the .devcontainer directory and pre-installs all dependencies from uv required to develop, test and build the project.

The devcontainer also installs the prek hooks and configures the VSCode python extension to use the appropriate python interpretor and pytest paths.