DDS15 — Specify Publishers with PRESENTATION access_scope GROUP should use same order for DataWriters

When PRESENTATION access_scope is GROUP samples need to e ordered across DataWriters. This is very hard/impossible if some writers use source_timestamp and others reception timestamp order

Propose that this is not allowed. If PRESENTATION access_scope is GROUP then all writers must have same ORDER. E.g. as writers are created if one is not consistent it should give an error