Connect users to organizations and CoC's

[cecilia-donnelly]

Each user needs to be connected to an organization and thence to a continuum of care in order for the API to handle consent and sharing correctly. I think consent and sharing is a separate issue, which is yet to be filed. I'll link it from here once it exists.

In the future, the TMP_USER table should have keys to the TMP_ORGANIZATION table and perhaps to the TMP_PROJECT_CONTINUUM table, or to a table specifically for continua of care (CoCs). For now, we'll add placeholder string columns to the user table for those values.

[cecilia-donnelly]

See #81. Both of these are fixed in the feature-sharing branch, so I'll close them once it's merged.