Support for Rigaku PXRD rasx format

[MJCliffe]

The Rigaku rasx powder x-ray diffractometer format is not supported, but is fairly widely used.

[ml-evs]

Got an example file we can add to the repo for testing (otherwise I can look myself)? We can add it at the same time as #1060

[MJCliffe]

Here you go:

JO_KL_16_ZF_3_60deg_0.02step_12degpermin_001.rasx.zip

[ml-evs]

That's a fun one, the .rasx "format" is itself a zip file that stores a simple txt file with basically xy data Profile0.txt and an XML file MesurementConditions0.xml [sic] that has some useful (and some less useful) info we can extract. Might be one for @be-smith to go for (assign yourself if you are interested), otherwise I can take a look next week.

[be-smith]

Out of interest @MJCliffe, do we know what the third column is in the data file? I can't find anything in the XML file that definitively explains it.

Another question, do we expect only one pattern per .rasx file? Or could it unzip to contain many patterns?