Fix Paginating, Sorting, and Searching Issues Within "Research Outputs" Tab

[aaronskiba]

Fixes #935

Changes proposed in this PR:

• Add scope :search to ResearchOutput model: e289fba9b0cbe4af4699455cf08adca8f597dac1
  • Search query is performed by research_outputs.title (case-insensitive)
• Create app/controllers/paginable/research_outputs_controller.rb 3c5a478feacc9bb9a8e69abd93579c70af29a207
  • This new controller fixes the following features on the /plans/:plan_id/research_outputs page:
  • The clickable pagination options (e.g. View all,1,2,Next,Last)
  • The search box (for research_outputs.title matches)
  • The clickable sorting arrows