Merge branch '23.0-McEventCollection_p7-TP-Convertors' into '23.0'

McEventCollection_p7 TP Convertors

See merge request atlas/Athena!65249

Version of the new McEventcollection_p7 TP convertors for the barcode migration. They shouldn't be written out yet, p6 is still set as current.

@jchapman @averbyts