fix #35091: measure properties dialog fixes

Apply button was applying changes but not doing an update() to force relayout.  It also lost selection.  I fixed that too, and actually made it so the selection tracks if you press the next/previous measure buttons, so you can see which measure you are actually working on.  I thought I remembered an older issue for that but cannot find it.  I also fix the minimum value for the "Layout stretch" control, which was stuck at 0.90 and would not show you values less than that even if you reduced stretch less than that with the keyboard shortcut.
Any reason why not selecting single m ?