Loads epic tree into a data structure
with epic id, iid, issue count and parent_id

Add lazy resolver

Connect CTE to a lazy resolver, which does a bulk
query for all the epic aggregate (weight and count)
rather than get a separate query for each. This also
prevents us from having to get information we already
have since one requested epic might be a child epic
of another.

Connect aggregate results with GraphQL type
- Use a PORO to represent the data via method exposure
Put together the recursive logic to sum the counts/weights
while separating them by graphql facet (count or weight_sum).