Add NIST infiltration method

[mdahlhausen]

Pull request overview

• add method to add NIST infiltration correlations to a model
• add supporting methods for NIST building type
• add methods to invert schedules
• add method to get the HVAC schedule from the model
• add tests for all the above

Pull Request Author

• [x] Method changes or additions
• [x] Data changes or additions
• [x] Added tests for added methods
• [x] Documented new methods using yard syntax
• [x] Resolved yard documentation errors for new code (ran bundle exec rake doc)
• [x] Resolved rubocop syntax errors for new code (ran bundle exec rake rubocop)
• [x] All new and existing tests passes

Review Checklist

This will not be exhaustively relevant to every PR.

• [x] Perform a code review on GitHub
• [x] All related changes have been implemented: method additions, changes, tests
• [x] Check rubocop errors
• [x] Check yard doc errors
• [x] If fixing a defect, verify by running develop branch and reproducing defect, then running PR and reproducing fix
• [x] If a new feature, test the new feature and try creative ways to break it
• [x] CI status: all green or justified

[mdahlhausen]

Three thoughts:

• It may be better to have a method that returns the HVAC schedule for a subset of zones, not the full model. Though that is easy to add later
• The method that adds infiltration probably should be separated from the method that sets the infiltration schedules. The reason being is that we'll want to add infiltration values in the off conditions for design sizing for HVAC systems, and then later adjust the infiltration on/off schedules to account for HVAC system operation.
• We don't have a way to account for the cycling nature of HVAC systems and moving between on/off infiltration regimes