Added Serialization component

updates jobs:

mwext-Ask-testextensions-master
mwext-Serialization-jslint
mwext-Serialization-lint
mwext-Serialization-merge
mwext-Serialization-phpcs-HEAD
mwext-Serialization-testextensions-master
mwext-Serialization-whitespaces
mwext-Wikibase-client-tests
mwext-Wikibase-repo-tests
mwext-Wikibase-testextensions-master
mwext-WikibaseQuery-testextensions-master
mwext-WikibaseQueryEngine-testextensions-master

Change-Id: I4e80630d5a967f3257666362e44d51d15c594838