Add support for legacy state/commandDefs to ComponentManager

Added methods to convert legacy state/stateDefs/commandDefs to
the new trait definitions and components and functions to convert
the trait definitions/component tree back to old commandDefs and
state.

Change-Id: Ia03142c53d00bbc4f880389166982167e3c8b1e9
Reviewed-on: https://weave-review.googlesource.com/1787
Reviewed-by: Vitaly Buka <vitalybuka@google.com>