Updated for Foundry v12

The Foundry module has been updated for version 12 of Foundry. You can find both versions of the module here - https://foundryvtt.com/packages/pf2e-heroic-variant

No functionality has been added, removed, or changed. The update is designed to work exactly as the v11 version did.

The updated version has been verified on Foundry v12.327 + PF2e System v6.0.1, as well as Foundry v12.331 + PF2e System v6.3.1.

With one exception, the port was rather simple. But the exception took a while to resolve - There was a change in the underlying token update logic between Foundry v11 and v12 which broke the automation for Phalanx Bonus. I was told that the logic may change again in v13, so I have tried to make it extra robust. But I'll have to keep an eye on it when v13 comes out.

Also, this was my first time updating a Foundry release. Didn't expect to spend as much time just in the mechanics of creating separate release versions. Thankfully, there's no wait time or approval process involved in just updating a release.