Make numtracker configurable per plan

Currently numtracker does not have a functionality of changing sub-directories per plan. You can only configure this only before the plan starts using the numtracker CLI / make calls to the graphql endpoint

## Acceptance Criteria
- You are able to change the sub-directory path per plan

Start by tracing how numtracker configuration is passed through the CLI and the GraphQL endpoint before a plan starts. Identify the plan-level configuration path and verify the sub-directory can be changed independently for each plan.

Written by the indexing model from the issue text.