Fix NuGet driver support when props import early

[ntoskrnl7]

Summary

• move driver/app mode defaults from crtsys.props into crtsys.targets so driver support is evaluated after WDK project configuration is available
• have the package provide driver exception handling and Inf2Cat local-time defaults
• update both NuGet consumer tests to import crtsys.props early, matching the problematic packages.config/native NuGet import shape
• update Test-CrtSysNuGetPackage.ps1 to install crtsys into the default versioned packages/crtsys.<version> folder and pass that installed package root into MSBuild
• update the driver consumer test to rely on the package for /EHsc

Validation

• XML parsed for crtsys.props, crtsys.targets, crtsys_nuget_test.vcxproj, and crtsys_nuget_app_test.vcxproj
• PowerShell parsed for Test-CrtSysNuGetPackage.ps1
• git diff --check
• manual MSBuild driver repro using a copied WDK driver project with early crtsys.props import and no consumer-side /EHsc or Inf2CatUseLocalTime workaround:
  MSBuild.exe MyDriver1.vcxproj /t:Rebuild /m:1 /p:Configuration=Debug /p:Platform=x64 /p:SignMode=Off /v:minimal
• NuGet app consumer builds with early crtsys.props import and a versioned CrtSysPackageRoot path:
  • Debug|x64
  • Release|x64
  • Debug|Win32
  • Debug|ARM64

Notes: the manual driver repro produced MyDriver1.sys and a catalog with Inf2Cat signability errors/warnings reported as None. The app builds stayed in header-only app mode with CrtSysUseDriverSupport=false.