Update Temperature Capacitance Multiplier to 7.0

[afontani]

Pull Request Description

Closes: #1161

After discussion and recent investigations into better understanding the resilience impacts of the ResStock timeseries results for power outages and load-shifting events, there is some evidence that the amount of thermal mass in ResStock is under-predicted. A quick (although non-physical fix) is to increase the temperature capacitance multiplier. A recommended number of 7.0 has been suggested by @jmaguire1. There are multiple efforts currently trying to leverage ResStock in these applications. While work is being done to better figure out a better solution, a quick fix is implemented to get the results in the acceptable range.

See related discussion in the attached issue for more details.

Checklist

Not all may apply:

• [ ] Tests (and test files) have been updated
• [ ] Documentation has been updated
  • [ ] If related to resstock-estimation, checklist includes data dictionary, source report, options saturation, options_lookup.
• [x] Changelog has been updated
• [ ] openstudio tasks.rb update_measures has been run
• [ ] No unexpected regression test changes on CI (checked comparison artifacts)

[afontani]

A couple screenshots from the datapoint comparisons...

[joseph-robertson]

Superseded by https://github.com/NREL/resstock/pull/1247.