fdo#72345: Fixed for Charts - Up Down Bars are missing after Round trip

UpDownBars missing after Roundtrip in case of LineChart.

Change-Id: Ia3e574aefb9436a2f5b2b88e8824625d09d35c38
fix an OOXML validation error with the last patch

Change-Id: I1aa1b2675a23b124666fce25807ddf65dfdcb8d5
also export hiLowLines for lineChart

Change-Id: I7b96fcb1e537517a80de87d997818d372d03f74a