Restore pre experimental field order when serialising to exml

[Auburn]

Take declared field order from the exe and use that to restore field order in exml

I only did some quick testing on this, but it seems to work as expected. The MBINs retain the new ordering

[monkeyman192]

Thanks for this!
It looks great.

I ran the extractor and sorted out the resulting files and the EXML fields now look to be in the same order as before the changes.
The only issue remaining is that list data which gets serialized is "exml field" order, but the way mbincompiler serializes list data means that it will serialize the data in lists in the order of the fields in the mbin, not in the exml.
I think this can be merged anyway despite that.