Add seperate output file for higher temporal resolution

[RegMeasures]

i.e. equivalent of Delft3D hist vs map file outputs

New output file should only output:

• lagoon water level in 1 location - maybe mean?
• outlet channel end positions
• outlet channel (minimum/mean?) width
• river inflow
• outlet discharge
• sea level
• wave condition

[RegMeasures]

Should also output MorDt (which changes over time due to adaptive timestepping - see #31 )

[RegMeasures]

Output file should include cumulative sediment transport as well as instantaneous