WinUI lightweight styling names

[TravisSpomer]

I'm going to be getting an Excel spreadsheet mapping the WinUI lightweight styling resource names to our standardized token names. I'll need to build a small console app that reads that and writes out token JSON with some platform overrides that can be merged with other token JSON from the plugin:

{
  "Meta": { "FluentUITokensVersion": 0 },
  "platform" : { "winui": {
    "Button": { "Base": { "Fill": { "Color": { "fullName": "ButtonBackground" }}}},
    "etc": "etc"
  }}
}

[TravisSpomer]

I added an example script in this commit and verified that it works with the sample data I have. We can use that script to produce token JSON with those mappings to feed into the pipeline along with regular tokens.