Fix # 19021 - Broken beam direction (again!)

Fix #19021 (again!)

A simpler (and yet correct in more cases) algorithm to find the direction of a broken beam.

Now finds the right direction in the great majority of cases without any attempt to 'understand' the rhythm or the time signature.
Might fail with some highly subdivided tuplets (10-plets or more) or sub-tuplets.

(I'm also working on making broken beam direction customizable to address special needs or the few cases when the algorithm fails)