Setting GraphQL depth limit to 10

[TomHawk123]

Context & Requests for Reviewers

This PR answers Issue #108

Tests

Ran locally and slammed the server with an overly complex query to confirm crashing of service. Implemented depth limit of 10 and tested:

Expected to Fail:

curl -s -X POST http://localhost:8080/graphql \
  -H 'Content-Type: application/json' \
  -d '{"query":"{ jobs { edges { node { item { submittedBy { roles { org { policies { rules { conditions { id } } } } } } } } } } }"}' \
  | jq .

Expected to Succeed:

curl -s -X POST http://localhost:8080/graphql \
  -H 'Content-Type: application/json' \
  -d '{"query":"{ __typename }"}' \
  | jq .

(Optional) Rollout Plan

After testing by reviewers, this should be able to rollout immediately.