Speed up weather processing

[shorowit]

Pull Request Description

Internally cache weather-processed data so that if, e.g., WeatherFile.new is called from different OpenStudio measures, we don't have to re-process the data. Also found a couple other opportunities to reduce processing related to weather.

Primarily speeds things up when:

1. Running unit tests (when measures are run repeatedly within the same openstudio/ruby call)
2. Running simulations where the BuildResidentialHPXML and/or BuildResidentialScheduleFile measures are used

CI results from running unit tests on:

• master: 43:43
• this branch: 36:49

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