Use Dependency in RunFirrtlTransformAnnotation

Change the type of the transform stored in a
RunFirrtlTransformAnnotation from a Transform object to a
Dependency[Transform]. This enables using either a class or an object
dependency.

Backwards compatibility is preserved with a deprecated apply method
for wrapping a Transform object in a Dependency.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>