Add MatchSerializerInjector

Add MatchSerializerInjector

Add injector where all match and match entry serializers will be
registered and call it from general SerializerInjector.
Add AbstractMatchEntrySerializer and MatchSerializer to be able to
actually create match entry serializers and serialize match body.
Add AbstractExperimenterMatchEntrySerializer to serialize match
entries with experimenter id.
Add match extension serialization to MatchSerializer, using match
extension converters. This needs to be changed later, to also remove
use of match extension converters.

See also: bug 7138

Change-Id: Ifa3f0d52b384b173cf639f7d00fd5a4a3e0d30f4
Signed-off-by: Tomas Slusny <tomas.slusny@pantheon.tech>