[SE-4852] Merge epic planning and sustainability roles

Part of process spring clean epic.

Tickets

• SE-4852

Open questions

Based on answers to these questions we might make some additional simplifications to responsibilities that are currently part of epic planning:

• Is anyone still referencing the Time / Estimates sheet? If not, we should remove the item about updating that sheet from the epic planning checklist.
  • Update (2021-10-07): We decided to keep the item about updating the Time / Estimates sheet for now, see this conversation for details.
• Should the responsibility for updating the Price list be moved to the Business Development Specialist role? The reasoning would be that when creating quotes, the Business Development Specialist has to look at and process information from discovery documents and corresponding estimation spreadsheets anyway, so adding any generic/reusable estimates to the price list as part of that work should be quick to do (and may involve less overhead overall than having the epic planning manager locate and review relevant results from discoveries as well).
  • Update (2021-10-07): We decided to move forward with this change, see this conversation for details.

Reviewers

• @jill_opencraft