Consolidated Swift framework search paths for precompiled frameworks

Targets that depend on many cached or external precompiled frameworks now consolidate their Swift framework search paths into a single generated per-target directory under Derived/FrameworkSearchPaths/Swift/<target> with symbolic links for uniquely named .framework and .xcframework artifacts, instead of passing every generated framework directory inline through OTHER_SWIFT_FLAGS. This reduces repeated filesystem work during Swift import resolution on clean builds of large projects.