Isolate cookiebar module JS

[sergei-maertens]

This puts the source code for the cookiebar module in its own source directory, allowing us to use Typescript to compile it down to JS.

Advantages:

• We can still build it and ship it with django staticfiles, similar to the 0.5.0b0 approach
• Additionally, we can expose the "npm package" on Github so that users can more easily include this in their own frontend pipeline and bundle it in their main entrypoint.
• We can use typescript for better robustness/less bugs & ship type declarations for users of Typescript themselves

TODO:

• Rewrite in TS
• Build 'package' from TS
• Expose package on Github (perhaps explore github packages as an alternative to npm registry?) not viable, see Need to make npm package public #120
• Ensure that the CI pipeline builds and publishes the build artifacts (so that npm install https://... works properly) publishing can't be automated at the moment
• Set up build tooling to bundle into static/cookie_consent/cookiebar.module.js

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.03%. Comparing base (175d7ba) to head (6c37cf0).
Report is 7 commits behind head on master.

❗ Current head 6c37cf0 differs from pull request most recent head 0191b88. Consider uploading reports for the commit 0191b88 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #119      +/-   ##
==========================================
- Coverage   96.08%   96.03%   -0.05%     
==========================================
  Files          12       11       -1     
  Lines         409      404       -5     
  Branches       70       52      -18     
==========================================
- Hits          393      388       -5     
  Misses         11       11              
  Partials        5        5              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.