[cml] Add compiler for CML to CM.

CML is the human-facing language for writing v2 component manifests. CM
is the binary format that gets stored in packages and translated
directly to FIDL.

CF-154 #comment add cml compiler

TESTED=unit tests

Change-Id: Id579f4decafc1ccca1500b00712fd2fe34b30aea
7 files changed