Sunset VAMSAS and rescue functionality

Jalview's VAMSAS menu provided a range of capabilities including provenance, interoperation between applications, and 'modification detection' to ensure the user was prompted to save work before quitting the application.

vamsas.jar was developed with castor - and whilst it could be migrated, there is neither funding or sufficient resource available to make this worthwhile, so we will drop the 'Vamsas' menu from Jalview, and target re-implementation of key capabilities within Jalview's core system.