SDD: fix "Evaporative Cooler Electric Power" request

A trailing ",hourly" in the report variable name caused an error.

[#79969370]
SDD: Remove request for 'System Node Mass Flow Rate' in air systems

Now favor standard density volume flow that was added recently.

[#79969370]
SDD: add report "Heating Coil Heating Rate"

[#79969370]