OZP-95: Get the RPC API code into the new repository.

1. Added standalone RPC bundles (owf-lite-*.html) to api projects.
2. Moved widgets to sample-widgets project since they are required both by container and standalone-container.
3. Updated existing API code to use Constants for rpc channel/service names.
4. Added ColorClient and ColorServer widgets to test RPC API.
5. Added infrastructure for test widgets not to be included during release.