Split off tooling from this repo

[dslmeinte]

Splitting off the tooling/ and valuesets/ parts of this repo into a separate repo, and its own NPM package.

This should have the following advantages:

• No dev dependencies (such as TypeScript), which should simplify local set up.
• Tooling can evolve independently of the rule sets in this staging repo.
• Split-off tooling can be geared towards ease-of-use outside this repo.
• Trigger calling of describe Mocha functions explicitly, instead of always running them.

(Could also integrate the split-off tooling into the eu-dcc-business-rules repo.)

[dslmeinte]

Could go in here (instead of a separate repo): https://github.com/ehn-dcc-development/eu-dcc-business-rules/tree/main/dcc-business-rules-utils

[dslmeinte]

The following issues in this repo should be moved to the new place as well: #47, #82, #90
(I closed those here.)