consent_form_type_code is _CL3. #3531.
Re-namespace code list loader. Done with #3531.

This puts it with the other MDES-related business.
Manage manual code lists in a separate file. Closes #3531.
Merge pull request #81 from NUBIC/3531-consent_form_type_code_list

Complete use of CONSENT_TYPE_CL3 for ParticipantConsent#consent_form_type

Looks like a fine change.