Allow users to choose which design days (0.4%, 1%, 2%) are imported

[aaron-boranian]

Allow users to choose which design days (0.4%, 1%, 2%) are imported, as detailed in this unmet hours post:

https://unmethours.com/question/13050/how-to-modifying-design-day-conditions-as-per-ashrae-901-g1221/

Migrated from UserVoice

[macumber]

Fixed in #791