[Board] Add endpoints to fetch all forums and fetch a forum and it's children by the forumId about collaction_api HOT 2 CLOSED

We need two calls for this.
One that fetches all forums
One that fetches a forum and all it's children

For the second call we'll need to query all forums parentList and return any that contain the initial requested forum. This way we know which forums contain which children.

let forums = await this.forumRep.findAll({ parentList: { in: [forumId] });

from collaction_api.

This is all covered in #133
Closing this as a duplicate

from collaction_api.