HPWH capacity inputs

[shorowit]

Pull Request Description

Addresses #1427. Allows optional HeatingCapacity and BackupHeatingCapacity inputs for HPWHs. Defaults same as before.

Checklist

Not all may apply:

• Schematron validator (EPvalidator.xml) has been updated
• Sample files have been added/updated (openstudio tasks.rb update_hpxmls)
• Tests have been added/updated (e.g., HPXMLtoOpenStudio/tests/test*.rb and/or workflow/tests/test*.rb)
• Documentation has been updated
• Changelog has been updated
• openstudio tasks.rb update_measures has been run
• No unexpected changes to simulation results of sample files

[shorowit]

Should probably disallow HeatingCapacity=0 for all water heaters in either the HPXML schema or OS-HPXML Schematron.

[shorowit]

Should probably disallow HeatingCapacity=0 for all water heaters in either the HPXML schema or OS-HPXML Schematron.

@joseph-robertson I am going to prevent zero for a water heater's HeatingCapacity, so e.g. that should prevent ResStock from modeling a HPWH with zero heat pump capacity. However, ResStock could still have an issue where a HPWH's BackupHeatingCapacity would end up zero. That is a legitimate possibility for some 120V HPWHs, so we can't disallow zero, but probably not what ResStock should use for its HPWH options.