Cache static and dynamic library products in the module cache

Static and dynamic library targets can now be cached as binary XCFrameworks alongside framework targets in the module cache. Cache warm emits xcodebuild -create-xcframework -library artifacts (with -headers when public headers exist), and restore now propagates cached library Swift module directories and C/Objective-C public header directories into generated targets, so projects with static or dynamic library targets can reuse module cache binaries across local and CI builds without rebuilding those modules from source.