Fix unity build with MSVC

Streaming std::optional<QtGrpc::CompressionAlgorithm> to QDebug fails
to compile with MSVC unity builds, as ADL lookup of the Q_ENUM_NS
registration can be shadowed depending on translation-unit merge
order. Exclude the affected files from unity batching.

Pick-to: 6.12
Change-Id: I194a255cb460402234232417b9c15e618f349f8a
Reviewed-by: Dennis Oberst <dennis.oberst@qt.io>