Add release control for all data sources

[irm-codebase]

Fixes #84, #80

Summary of changes in this pull request

• Improves version handling for all datasets. These are based on internal defaults.
• Ups geoBoundaries version to 6.0.0.

Reviewer checklist

• There are no pip dependencies in the module's environment files (workflow/envs/).
• All rules use pathvars (e.g., <results>) in their inputs and outputs.
• The integration test-suite is successful, including:
  • pre-commit.ci tests pass.
  • tests pass for all relevant OS configurations (linux, osx, windows).
• Module documentation is up-to-date, including:
  • INTERFACE.yaml mentions all relevant pathvars and wildcards.
  • README.md describes how to use the module and has the necessary citations.

[irm-codebase]

@brynpickering I've implemented some enhanced flexibility to the release handling of all datasets.
The release number is now part of the file path, and you can specify a release for all data sources.

In theory, we could make all data sources accept a 'release' version per country (like year for NUTS).
I did not add this because the other sources are not as stable / high quality as NUTS, and because it would mean a breaking change in the configuration (i.e., version bump).

We could consider this if mixing and matching releases within scenarios becomes attractive for these datasets.