feat(spec)!: retire the ADR-0078 conversion-conflict channel — onConflict / reservedNodeTypes, the notice types, the conflicts arrays and the FLOW_CONVERSION_CONFLICT 409

feat(spec)!: retire the ADR-0078 conversion-conflict channel — onConflict / reservedNodeTypes, the notice types, the conflicts arrays and the FLOW_CONVERSION_CONFLICT 409 #34354