PDBs reveal that these functions are also used in winspool.drv, but not imported from spoolss.dll to retain the client/server architecture.
As winspool.drv highly benefits from the MarshallUp* functions, I put them in a source file shared between spoolss.dll and winspool.drv.
The added API Tests cover my testing and all implemented features.
One more item done from https://reactos.org/wiki/Printing !
* Pass the correct handle to _RpcGetPrinter in GetPrinterW.
* Pass an empty string instead of a NULL pointer as wszComputerName to the GetPrinterLevel* functions, because this variable is later used as source for StringCbCopyExW.
* Don't check for GetLastError() == ERROR_SUCCESS in tests. Windows apparently only sets the last error in case of failure.
The Printing code should probably be changed similarly in a future commit.
Should fix CORE-14072
This may get more applications to work which previously called into the WINE-generated stubs (that throw an exception).
It also improves debug logs when the "winspool" debug channel is enabled. With such detailed debug logs, we may get an idea which winspool APIs need to be implemented sooner than others.
