All Test-Projects: Updated .NET Version to .NET 4.8

...ux/VectoAuxiliariesTests/My Project/Resources.Designer.vb

...Aux/VectoAuxiliariesTests/My Project/Settings.Designer.vb

VECTOAux/VectoAuxiliariesTests/VectoAuxiliariesTests.vbproj

VECTOAux/VectoAuxiliariesTests/app.config

VectoCommon/VectoHashingTest/VectoHashingTest.csproj

VectoCommon/VectoHashingTest/app.config

VectoCore/ModelbasedTests/ModelbasedTests.csproj

VectoCore/ModelbasedTests/app.config

VectoCore/VectoCore/VectoCore.csproj

VectoCore/VectoCoreTest/Properties/Settings.Designer.cs

VectoCore/VectoCoreTest/VectoCoreTest.csproj

VectoCore/VectoCoreTest/app.config

VectoCore/VectoCoreTest/packages.config