Fix Issues Building For Web on Windows

[BlueMagnificent]

Two issues are currently encountered when building Urho3D for Web on Windows.

1. While setting up a build by directly or indirectly calling script\cmake_generic.bat, an infinite loop will occur when the -D options is not followed by a space, see Infinite Loop in script/cmake_generic.bat #59. Example script\cmake_vs2022.bat build -DURHO3D_SAMPLES=1. This can easily be avoided by adding the needed space after -D. However when used with Emscripten's emcmake to setup for Web, the infinite loop will be encountered once more because emcmake emits the CMAKE_TOOLCHAIN_FILE and CMAKE_CROSSCOMPILING_EMULATOR build options with no space after -D.

   Additionally, emcmake emits the MinGW makefiles generator flag without quotes around MinGW Makefiles and this breaks CMake.

2. In Source\Tools\CMakeLists.txt, the CMake command to install PackageTool and BindingGenerator under the CMAKE_CROSSCOMPILING option specifies these files without an extension. When building for Web on Windows, the builds are successful but installation fails with error file INSTALL cannot find <path/to/file> because the file being looked for has no extension while the actual file that was built has .exe extension.

This PR fixes the above mentioned issues and was tested on a Windows 11 machine using Emscripten version 3.1.59 ( the latest version at the time of this post)

[klaussilveira]

Thanks! Sorry for the delay on this. We tend to be more active on Discord, so feel free to bug us there if a review is pending for too long.