Add additional workflow configurations, fix some issues

[kblaschke]

Added additional GitHub Actions workflows to test additional build configurations, e.g.:

• Using boost::filesystem instead of std::filesystem
• Build 32-bit binaries on Windows
• Build on Windows Server 2022 and 2025
• Build for armv7/x86_64 platforms on Android
• Build both x86_64 and arm64 binaries on macOS

Fixed a few build issues which popped up on the vcpkg update and adding the additional workflows:

• Added a missing include in the playlist implementation which broke the build when using MSVC and boost::filesystem
• Silenced a CMake warning if projectm-eval wasn't found externally
• Force CMake to use Boost's own CMake config package instead of CMake's internal find module

After merging, I'll cherry-pick those changes into the 4.1.x branch as well and then tag a new 4.1.6 release to fix the build issue.