SwiftPM warning control settings load and map to Xcode flags

Tuist now decodes and maps SwiftPM’s treatAllWarnings, treatWarning, and enableWarning target build settings into the same flags SwiftPM emits in OTHER_SWIFT_FLAGS, OTHER_CFLAGS, and OTHER_CPLUSPLUSFLAGS. Packages such as swift-dependencies 1.13.0 load without Tuist failing during package decoding, and the package author’s warning behavior is preserved in the generated Xcode project.