MSCX format: stave bracket type uses opaque syntax
Current syntax for stave brackets:
<bracket type="2" span="2" col="1"/>
I suggest replacing integer type with these more descriptive types, inspired by the language used on pp.514-518 of Elaine Gould's Behind Bars:
This is important because it appears in the diff when storing MSCX in Git or other version control, and it (could be) displayed by the Score Comparison Tool (though in this case nothing is displayed).
Aside: The "line" bracket is not mentioned in Behind Bars, so I don't recommend using it very often. I personally use it to indicate where I have been forced to use multiple staves for instruments that were shown as a single staff in the source edition, such as "Trumpet 2 in A" and "Trumpet 2 in C". It is unlikely that both trumpets will appear in the same system, so the line will only be visible in Continuous View, but in the rare case that both are visible I find it helpful to group them together visually (see an extreme example here).
Relates to #296654: [EPIC] Requires MAJOR version bump