StorageBase: Use std::shared_ptr<void> for c'tor / d'tor


Simplify internals a bit.

Change-Id: Iec87acac9cd69f99c1fcd8759c43a5a4f81ef5f5
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
commitda4aba009e87cdc09bcf49a87b2a87ef4ddc9f43
parent34e0f1207d9f8cf994a7ea71e7bb6219603fb000
authorJarek Kobus <jaroslaw.kobus@qt.io>
committerMarc Mutz <marc.mutz@qt.io>
commit timeMon, 1 Jun 2026 19:09:35 +0000