Use NoteColumns as X-parents for dynamics and lyrics (Issue 2245)

Until now, the X-parent of a LyricText and DynamicText was
a NoteHead.  This was a problem because LyricTexts and
DynamicTexts attached to chords with suspended notes were
aligned to the first note in input:

{ <f' g'>1\p <g' f'>\p }
\addlyrics { la la }

Aligning these grobs to whole NoteColumns makes sure that
the input order won't matter.  It may be better to align
them to the "main" noteheads (i.e. ignore the suspended
notes altogether), but that's topic for another patch.

!!!!!!!!!!!!!!!!!!!!!!!!!!!!
warning! there is a problem with flags, wchich are
included in NoteColumn extents...
!!!!!!!!!!!!!!!!!!!!!!!!!!!!