add wind farm LT distribution option

[aclerc]

This PR introduces a new use_test_wtg_lt_distribution setting on WindUpConfig. Setting this to false means the whole wind farm will be used to derive the LT distribution instead of just the test turbine.

This PR includes several other minor improvements such as:

• the hours required for a power curve bin to be valid hrs_per_mps has been increased which improves the quality of measured power curves but can slightly change results due to fewer valid bins
• plots are organised into subfolders named after the reference
• columns are ordered in the interim results file
• new uplift percentage plots
• the ops curve shift warning logic is improved