elixir.bat: Quote file paths

[wojtekmach]

Before this patch, if any of the boot paths contained spaces we got a failure:

This was also the cause of livebook-dev/livebook#2368.

Note we are also quoting non-path values as cookies for consistency so I double-checked and that is not problematic:

C:\Users\User\foo bar\foo>iex --sname foo --cookie bar
Erlang/OTP 26 [erts-14.1.1] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [jit:ns]

Interactive Elixir (1.15.7) - press Ctrl+C to exit (type h() ENTER for help)
iex(foo@WinDev2206Eval)1> Node.get_cookie
:bar

[josevalim]

💚 💙 💜 💛 ❤️

[wojtekmach]

@josevalim should we back port this to v1.15?

[josevalim]

There won't be a new Elixir v1.15 release. If your concern is Livebook, perhaps we can temporarily patch it there?

[wojtekmach]

Oh, ok. There's no rush. I'm updating Livebook to 1.16 anyway.