Delegate marcpattern language (reader/util) to Versa pipelines

[uogbuji]

Right now the pattern language used for marcpatterns is custom to pybf (implemented in reader/util.py). Since then Versa pipelines have taken on much of this capability, and there are confusing disfluencies between them. Time to just completely delegate to the Versa pipeline pattern language. This will involve adding as well as reconciling language features.