Cache static and dynamic library targets in the module cache

Static and dynamic library targets are now treated as cacheable binary products in the module cache. Cache warm creates library XCFrameworks with xcodebuild -create-xcframework -library and includes public headers when the source target declares them. On restore, the standard HeadersPath from the XCFramework Info.plist is mapped back into header search paths and Swift module directories for generated targets, so static and dynamic library targets can now be reused across local and CI builds alongside frameworks.