fix: cmd-shim not identified if placed outside `node_modules/.bin/`

[patrickkfkan]

I have a node executable installed globally with npm i -g . Because of this, the cmd-shim was not placed in node_modules/.bin/. On Windows, this caused cross-spawn to escape arguments only once.

This PR inspects the contents of the target file and if it can obtain the wrapped command, it will take it as cmd-shim and escape arguments twice.