Add "did not ask" to checklist curated responses

[afreidz]

FEATURE / OUTCOME As a – User I want to – be able to log a checklist response as "did not ask" So that – I can have a record of tasks that I was unable to ask the respondent

I will know I am done when:

• I can select an option for "did not ask" on checklists on
  • the moderator session view
  • the user-facing checklist link