User management UI

- Add validation
- Add basic user API
- Select multiple programmes and projects.
- Load selected user's data.
- Static page when saved.
Fixes after code review.
Merge pull request #163 from MastodonC/feature/user-mgmt

User management
First attempt insert/get tests.
Bump schema_gen dependency.
Add sensor test and full test.
Added cleanup method.
Change to deftest.
Add test selector.