feat: Adopt UAX-31 compliant dataset names (#702)

* update dataset names

* maxsplit 1

* feat: add uax-31 compliance to build_datapackage.py

This commit introduces a new naming strategy to ensure every resource has a unique, UAX-31 compliant identifier.

The new implementation works as follows:
- A preliminary scan of the `/data` directory identifies dataset basenames that have multiple file extensions.
- A new `make_uax31_name` function sanitizes the filename to create a valid Python identifier (replaces hyphens, prefixes numbers).
- For datasets with multiple formats, the file format is appended as a suffix to the name to guarantee uniqueness.
- Note: Adding a new format for an existing dataset will rename the original resource to include a suffix.

* feat: Enforce snake_case for dataset names in datapackage

Updates the `build_datapackage.py` script to ensure all generated dataset names are `snake_case`.

The changes include:
- A new `to_snake_case` helper function to convert camelCase strings.
- The `make_uax31_name` function now uses this helper to sanitize all dataset names before they are written to `datapackage.json`.
- This resolves issues where filenames like `londonBoroughs.json` would result in a non-standard `camelCase` identifier.

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Co-authored-by: dsmedia <[email protected]>

Author: mattijn