Enable nxspe reader for instrument data

[cmarooney-stfc]

Draft PR (still debug info in some source) to test reading of these new files with the existing nxspe reader. the changes test the ability to read.

The code to populate instruments with the additional information has not yet been added

This supersedes PR #1714 which is corrupt because it still contains references to the too-large original nxspe test files. The ones here have had their energy bins reduced in size from 640 to 10 to fit within the github limit. The python script used to shrink the files has also been added

[abuts]

Comment:
I do not understand the meaning of these changes.
Either you want to read whole instrument from nxspe -- then read_instrument method should be present on nxspe loader, and a dumb read_instrument returning empty instrument on other loaders. and read_instrument shoild return whole insturument.

Or you may want to read part of the instrument -- then bunch of the methods for components should be present with dumb equivalents on the interface.

Here we have some unclear mixture which reads instrument but uses other fake "read" methods to construct instrument. The purpose of such implementation is absolutely unclear to me and IMHO, highly confusing.

[abuts]

Comment:
Adding multiple binary files to repository is very bad practice.
As far as I understand, all these files differ by instrument only and you test generation/saving the instrument and then recovering them.

Why not to generate majority of these files on the fly, save it and test loading and add one small sample file with one sample instrument to validate code consistency? Or even test generation against test with save and autogenerate all other files and test their loading. You are testing these things anyway.

[abuts]

Comment:

Hate discussing naming conventions, but why this read does not read anything? It should open appropriate hdf group, throw if not found and call Moderator constructor if found. (or init moderator method). Alternatively, it should return empty moderator||instrument||whatever

as far as I understand, you are reading nxspe files, and nxspe instrument is a structure, generated by other application. binary-serializable should not be used to save nxspe instument. In nxspe, you should be saving a structure similar to the structure, obtained from MANTID. Then recover this structure as instrument. Optianally, you may want to recover instrument components.

Here you should read a structure or partial structure, and place the task of converting the structure into meaninful classes onto class constructor or init method. Why to invent some intermediate workflow?