Fix incorrect AE address ID for `BGSFootstepManager::Singleton`.

Bump version numbers for 3.6.0 release.

Switch spdlog/fmt to static linking instead of header-only mode.

The header-only mode was a workaround for issues experienced in the past with
spdlog/fmt interaction. Those issues appear to be fixed so that change can be
reverted.

Fix `OutputDebugString` symbol being incorrectly resolved.

Fix `BSAnimationGraphManager` offsets.

Remove undefined `ExtraDataList` functions which were removed upstream.

Fix reversed meaning of the new post629 structs flag.

Final fixes for SKSE 2.2.0 plugin API support, bump version for release.

Add Xbyak to Conan dependencies.

Make builds use strict standards compliance.