#1808 Add support for execution of reference entities Pull request opened by troychiu TL;DR As title Type ☐ Bug Fix ☑︎ Feature ☐ Plugin Are all requirements met? ☑︎ Code completed ☐ Smoke tested ☐ Unit tests added ☐ Code documentation added ☐ Any pending items have an associated Issue Complete description I added the support for execution of reference entities, including reference task, reference workflow, and reference launch plan. Although the integration tests are not enabled right now, I have added them. Tracking Issue flyteorg/flyte#3627 Follow-up issue NA flyteorg/flytekit ✅ All checks have passed 2/2 successful checks