fix #30061: markup appear in textline properties for 1.3 scores

The problem is the begin, continue, and end texts in the dialog are not laid out - only the copies made for the individual segments are.  A layout or equivalent has to happen at some point so we can get the plainText to put in the dialog.  I elected to do the layout right in the dialog initialization, then I take the plainText.  I'm sure there are other ways that would work - but I can tell you from experience there are a lot of ways that *don't* work :-).