Migrate the mailing list API endpoint to Quarkus

Similar to eclipsefdn-downloads-api#1 (closed), we decided to move some existing APIs to Quarkus.

The mailing list endpoint is defined here: https://api.eclipse.org/#tag/Mailing-Lists

• Retrieve metadata for all the mailing lists https://api.eclipse.org/#operation/FetchMailingLists
• Retrieve information for a specific mailing list https://api.eclipse.org/#operation/RetrieveMailingList