Enable Namecoin on Windows Nightly

This PR enables Namecoin on Windows Nightly. Notes:

1. The user must install Python themselves; Tor Launcher will find Python automatically if it's in the PATH. This can be improved in a subsequent MR.
2. The TOR_VERBOSE_NAMECOIN=1 environment variable will enable verbose console logging of Electrum-NMC and StemNS.
3. Currently, if StemNS or Electrum-NMC is killed, Tor Launcher's error will indicate that Tor was killed. This can be improved in a subsequent MR.
4. Translation strings for new error messages haven't been added. This can be improved in a subsequent MR.

Everything else works pretty much the same as the GNU/Linux support (e.g. the TOR_ENABLE_NAMECOIN=1 environment variable is used to enable Namecoin at runtime). I also bumped the Electrum-NMC checkpoint, as it was getting a bit outdated.

Fixes tor-launcher#40001 (closed)

Fixes #40022

Fixes #40042 (closed)

(First time using GitLab's MR functionality for Tor stuff, so please let me know if my MR style needs revision.)

Huge thanks to Cyphrs and the Cyberia Computer Club for sponsoring this port.