Finalize Invision prototype with 18F content and minor feedback changes

[austinhernandez]

Final version here

• implemented @nicoleslaw's feedback
• added closed and opened filter screens
• added search results for "all" and "only recruiting"

[austinhernandez]

Source files are here for @onezerojeremy whenever you're ready to make changes - clinicaltrials_prototype-3-28-ah.sketch

[acolter]

Closing all issues from Phase 1