validate that causes cannot be added inside of causeProjects field

[divine-comedian]

we should ensure that when the causeProjects field is being updated with new projects that NONE of the added projectIds are of projectType='cause' if this happens for whatever reason it will cause massive problems with how we evaluate project data and read views on the FE

AC

calling create cause mutation on the impact-graph

• trying to create cause via API, adding in a projectId of a cause, the impact-graph will fail or reject this mutation