Infra: Add Nginx Docker compose component

[pitastrudl]

Some setups might not have their own loadbalancer or reverse proxy in front. For this reason, a Nginx setup is needed. One was done to support the setup for the dev server.

• Should we have one nginx block in each of the corresponding repos? (frontend, api)
• Should all of it live inside the infra repo?

[pitastrudl]

Remember to also add all the CSP headers as well, though this can also be set in Keycloak