webview External Dependency PoC for Go/Windows

Verify that build does not work due to missing WebView2.h header:

go build

Expected output:

# github.com/webview/webview
In file included from webview.cc:1:
webview.h:839:10: fatal error: WebView2.h: No such file or directory
  839 | #include "WebView2.h"
      |          ^~~~~~~~~~~~
compilation terminated.

Use generator to fetch dependencies and set up Go environment:

go generate

Optionally restart the terminal to make sure that there are no lingering variables that help make this work.

Try to build again:

go build
basic.exe