ExternalSpillableMap should set all member variables (including newLocation and oldLocation)

[n3nash]

The spillable map at the moment spills the HoodieRecord to disk. After it spills the record to disk, when recreating the record, it sets the hoodieKey and data back to the HoodieRecord, the constructor for HoodieRecord sets the newLocation and oldLocation to null as opposed to the actual value that was set during the index tagging process.
Since BloomIndex does not do any post operations with these fields, this issue was not seen there, but for HbaseIndex, the updateIndex() actually looks at these location variables and updates Hbase.

[n3nash]

Fixed as part of #419