SFMS: Store Fuel Lookup Values for each processed fuel grid

**Describe the task**
Processed fuel grids assume the static SFMS values in `sfms_fuel_types`. If these change we have no flexible way to reference the new values

**Acceptance Criteria**
- [ ] `sfms_fuel_types` should reference a separate table for lookup values

**Additional context**

Start by locating the sfms_fuel_types table and the code that processes fuel grids, then inspect how its static lookup values are stored and referenced. Done means sfms_fuel_types references a separate lookup table so each processed fuel grid can retain the values used at processing time.

Written by the indexing model from the issue text.