Define x86 preset on Windows x64 host using Ninja generator

Usage
3

The solution was to add toolset:

{
    "name": "x86-debug",
    "inherits": "windows-base",
    "architecture": {
        "value": "x86",
        "strategy": "external"
    },
    "toolset": {
        "value": "host=x86",
        "strategy": "external"
    },
    "cacheVariables": {
        "CMAKE_BUILD_TYPE": "Debug"
    }
}