Binary cache supports ARCore-style nested static Objective-C xcframeworks

Tuist now correctly handles static Objective-C xcframeworks whose public headers live in a Headers// subdirectory, such as ARCoreGARSession and ARCoreGeospatial. The mapper distinguishes these nested layouts from flat ones and uses the xcframework’s own module map with the Headers root on the search path. This resolves both ‘file not found’ and ‘shadowed module’ build errors when these xcframeworks are consumed through the binary cache behind a dynamic framework.