Move modules/Ushahidi -> web/

Summary:
Move modules/Ushahidi -> web/
Replace all references to UshahidiUI with web/

Still a kohana module but a precursor to T211

Test Plan: - Check UI still loads

Reviewers: eyedol, shadowhand

Maniphest Tasks: T211

Differential Revision: https://phabricator.ushahidi.com/D245