Develop sampling approach for energy demand data

[willu47]

Design a sampling scheme which produces a good compromise between

• peak (for estimating system size)
• total energy supplied (to meet demand), and
• emissions (representative mix of peak and average energy)

Compare this to full-year run to assess accuracy of sampling approach.

[tomalrussell]

• [x] Create adaptor module
• [ ] Add parameter to pick sampling approach
• [ ] Run each sampling approach (parameterise using narrative)

[tomalrussell]

Alternative sampling provided by #169