Axis Id attribute of top-level NC.xti Axis may differ from per-axis .XTI Axis Id attribute [LCLSECSD-730]

[klauer]

When saved in a separate file, the Axis Id attribute of top-level NC.xti Axis may differ from per-axis .XTI Axis Id attribute.

We currently use the axis one and not the NC-defined one.

pytmc/pytmc/parser.py

Lines 1759 to 1762 in 411820b

	self.axis_by_id = {
	int(axis.attributes['Id']): axis
	for axis in self.axes
	}

TODO: Warn (or error) if the two differ to avoid confusion in the future.

e.g.,
https://github.com/Mbosum/lcls-plc-lamp-lv17-motion/blob/bfba8bc10cd8ad05ffd1c757fd00a421e3cebfe5/lcls-plc-lamp-lv17-motion/_Config/NC/NC.xti#L22
vs
https://github.com/Mbosum/lcls-plc-lamp-lv17-motion/blob/bfba8bc10cd8ad05ffd1c757fd00a421e3cebfe5/lcls-plc-lamp-lv17-motion/_Config/NC/Axes/SamplePaddleX.xti#L1350

[slactjohnson]

Related to JIRA ticket here: https://jira.slac.stanford.edu/browse/LCLSECSD-730