Extends Rest api for baskets

Closes (partially) #345 (closed)

What does this MR do?

Adds a Rest controller for foodbaskets. This includes routes to

• list the user's basket: /api/baskets/mybaskets
• list the coordinates of all baskets (for the map): /api/baskets/coordinates
• retrieve details of a basket: /api/baskets/basket/{id}
• publish a basket: /api/baskets/add
• remove a basket (set status to deleted): /api/baskets/remove/{id}

How confident are you it won't break things if deployed?

Quite sure. The controller is on top of the gateway, so the web page itself should not be affected. I also included tests.

Links to related issues

#345 (closed)

Checklist

• added a test, or explain why one is not needed/possible: added tests
• no unrelated changes
• asked someone for a code review
• joined #foodsharing-beta channel at https://slackin.yunity.org
• added an entry to CHANGELOG.md (description, merge request link, username(s))