Generate DocC-compatible module maps for package target dependencies

DocC builds for generated projects no longer fail on Swift package targets whose public Objective-C headers import a sibling module from the same package (the Firebase case). Tuist derives missing target edges from concrete #import/#include references when needed and copies dependency framework module maps to the canonical Modules/module.modulemap location so Clang ExtractAPI can discover them. The original MODULEMAP_FILE sanitization for non-DocC framework targets is preserved.