MongoDbIO add support for projection

MongoDbIO.read should have support for Projection, so that we can limit the document size that is retrieved, for example:

pipeline.apply(tableName + " read", MongoDbIO.read()
.withUri("mongodb://" + srcMongodbManagment.getMongodbConnection())
.withProjection("time")
.withDatabase(options.getDBName())
.withKeepAlive(true)
.withCollection(tableName))