Be able to initialize Agreements step of the workflow with a draft submission (1.5d)

[jabrah]

Depends on #19

• Should start on the first agreement that the user has not yet agreed to
  • If all agreements have been agreed to, display (first|last) agreement
• Should initialize "agree" element/checkbox based on the agreements the user has previously agreed to
• Tests for above

This will include filling out the submission state