CPS-950: Refactor existing model sync code into separate package

CPS-950 - Getting issue details... STATUS

Refactor existing model sync code into separate package and classes so it can be used by both sync(current) service and new watchdog process.

Keep all sync  method(s) in a separate class so that it can be tested easily.

Method name that need to be refactored > Class name : org.onap.cps.ncmp.api.impl.NetworkCmProxyDataServiceImpl > Method name : syncAndCreateSchemaSet

1. Created new package(s) for synchronization code

1. 1. org.onap.cps.ncmp.api.impl.sync.model
   2. org.onap.cps.ncmp.api.impl.sync.data
2. Break down syncAndCreateSchemaSet method into separate / multiple methods

1. 1. syncAndCreateSchemaSet(yangModelCmHandle);
   2. createAnchor(yangModelCmHandle);

       3. Take out common code at one place so that it can be resued.

Currently test is in : org/onap/cps/ncmp/api/impl/NetworkCmProxyDataServiceImplModelSyncSpec.groovy