take constitution governance out of org and put in own module

[4meta5]

called meta

it will also have a map to register vote thresholds for setting defaults for org governance in other modules

map DefaultId => Option<VoteThreshold>

and simplify org

org becomes a weighted-membership module; the parent - child org relationship should be expressed as a set in the runtime instead of fields within the OrganizationState struct

double_map (OrgId, OrgId) => Option<()>