Update Cold Climate HP model

[jmaguire1]

Update the ASHP model in OCHRE to match the updates that are being done to the OpenStudio/HPXML model.

• [ ] Allow taking new inputs for cold climate performance (corresponding to NEEP data)
• [ ] Update curves based on new inputs
• [ ] Cold climate capacity retention
• [ ] Start-up capacity degradation
• [ ] Lockout temperatures
• [ ] Backup supplemental heat staging
• [ ] CTA commands (low priority)
• [ ] Look at 2-speed staging in OCHRE
• [ ] Defrost control

[jmaguire1]

Adding documentation from Neal Variable Capacity Heat Pumps Algorithm.docx

[jmaguire1]

https://github.com/NREL/OpenStudio-HPXML/blob/e9a227ea2a154dbafdbc81dfc1a57d19da265af3/HPXMLtoOpenStudio/resources/hvac.rb#L1256-L1350

There's new correlations being used to calculate performance based on HSPF/SEER and NEEP data. I don't know that this fully replaces what we have in the .csv files for equipment properties, but when we implement this we should revisit the spreadsheet and see if we can't derive correlations for other parameters.