Enhancement: Check for shell builtin before wrapping

The introduction of wrapping commands given the possibility it is a shell builtin keyword on *nix envs results in potential issues in projects relying on npm_lifecycle_script env var given the value has now changed.
This was introduced in https://github.com/npm/cli/commit/fdc3413019c2f34f1fde35449e5f3a6b0fb51ba2

Instead of wrapping all cmds it would be beneficial to first check if the command is a builtin prior to wrapping.
Something such as ...

  if (!isWindowsShell) {
    if (args.length > 0) {
        let builtin = false;
        exec(`type ${args[0]}`, (error, stdout, stderr) => { if(stdout.includes('keyword')) { builtin = true; } });
        if(builtin) {
          args[0] = '"' + args[0] + '"';
        } 
    }
  }

Start by tracing the command-wrapping behavior introduced in commit fdc3413019c2f34f1fde35449e5f3a6b0fb51ba2, then inspect how npm_lifecycle_script changes for shell builtins on Unix environments. Done means builtin commands are checked before wrapping and projects relying on the original environment variable value no longer regress.