As a staff person I want to create a future RUP for an agreement that already has an approved RUP so that the approved RUP will be in place in a timely fashion

See #156 for background on the time considerations when preparing RUPs
See https://github.com/bcgov/range-api/issues/56 for general info on versioning
Where an existing plan is already in place a situation may arise where:
- approved version of the plan exists
- staff starts "next-plan" preparation
- "next-plan" may be signed by agreement holder AND decision maker but does not become "current-plan" until "current-plan" term ends (becoming "former-plan") and

**Functional Plan Types** (NB related to system statuses but does not capture all of those needed )
- "*current-plan*" -- plan is signed by all parties and is current legal version
- "*next-plan-draft*" -- plan start date in the future -- not yet signed by all
- "*next-plan-approved*" -- plan start date in the future -- all parties have signed
- "*former-plan*" -- a plan that was "current-plan" exceeds it's original expiry (or extended plan end date) and is no longer legal

# Requirements
- [ ] staff can start a next-plan-draft from scratch
- [ ] staff can start a next-plan-draft making full copy from "current-plan" except usage and yearly schedules data (most likely workflow)
- [ ] usage data should populate all available years data from FTA and populate any years outside of current term with final year of agreement data
- [ ] staff and agreement holders complete all tasks from draft through approved including considering #156 (plan date(s) extend beyond current agreement expiry)
- [ ] next-draft plan status clearly visible as being "NEXT" and whatever status is (ex. awaiting feedback, or submitted for review or decision)
- [ ] approved next-plan keeps "next-plan" status until "current-plan" reaches expiry becoming "former-plan" and "next-plan's" start date is reached