Check versification mismatch for Serval debugging

[Enkidu93]

Check whether the USFM matches the versification. If not, place information about how it's mismatched in the ExecutionData so that Serval developers can debug versification-related issues more easily.

Note that there are some kinds of versification mismatches which we may be unable to detect - i.e., if the mismatch is only observable if you look at the verse text itself - but we can at least confirm that the USFM structure matches the versification type and custom.vrs.

[Enkidu93]

Beginning this issue by creating a UsfmParserHandler in Machine to check versification mismatches.

[Enkidu93]

I'll do this one while I'm in that code: sillsdev/machine#318