Remove Working Group API proxy and update JS to use new WG API

As the functionality for working groups grows, it is well on its way to becoming its own fully-fledged API. Future plans for the API will carry us to that point so we should start building out the standalone solution. This better enables plug and play of other APIs without the weight of the whole membership service as well.

The initial project is created, and will soon have the basic Quarkus framework as a starting point. There will be work to migrate the current functionality and then improve it in the coming months.

https://gitlab.eclipse.org/eclipsefdn/it/api/eclipsefdn-working-groups-api