Adds testing and linting of the frontend

GREG-41: Adding custom link

See merge request !50

Add basic theming support.

See merge request !51

Issue: GREG-40

- Add global styling. Remove the old css file.
- Start on the themes

Issue: GREG-40

Enable absolute imports

See merge request !48

Configure prettier to prefer no semicolons. Format all files.

See merge request !47

i18next support

See merge request !46

Issue: GREG-37

Feature/hasconsented

See merge request !43

Adds a setupProxy config:
The package i18next-http-backend and the proxy config does not work
together. The proxy setup hijacks the loading of the translation files.
Adds a setupProxy.js to only proxy /api.

Adds a simple prettier config

Issue: GREG-37

Switch from next.js to create-react-app

See merge request !45

Issue: GREG-35

Add a barebones nextjs project

See merge request !44

Issue: GREG-35

Add pipeline and coverage badges to README

See merge request !42

Useful for checking that there are consent objects for a certain
person for all the mandatory consent types.

Identity model changes

See merge request !41

Use CloudEvents format for message publishing

See merge request !40

Test more things

See merge request !39