Migrate test framework away from Karma

[Zarthus]

Is your feature request related to a problem? Please describe.

Karma does not support Node JS 18+ (unless you run export NODE_OPTIONS=--openssl-legacy-provider [NOT RECOMMENDED]). GitHub Actions actively prohibits toggling this option on.

NodeJS 16 will EOL in 2 months time: https://endoflife.date/nodejs

It is unclear for how long GitHub Actions will keep supporting Node 16, but we should assume the EOL date.

Describe the solution you'd like
We need to migrate away from Karma to another testing framework, e.g. Jest

This may be partially automatable with something like https://jestjs.io/docs/migration-guide#jest-codemods

Describe alternatives you've considered

1. Run Github Actions on Node 18 with --openssl-legacy-provider (not possible)
2. Keep running the CI on node 16 but target development on 18 (not feasible long-term)
3. Use a different CI infrastructure than GitHub actions to run our testsuite (not feasible long-term)

Additional context

More context: #4100

karma-runner/karma@450fdfd

[martijnrusschen]

This is an important initiative. Any help we can get to migrate to Jest would be welcome. Using code mods may be give us a good start on getting the migration done.