Support SwiftPM warning-control settings in generated Xcode projects

Tuist now decodes and forwards the newer SwiftPM warning-control APIs: .treatAllWarnings, .treatWarning, and .enableWarning. Packages that declare them (swift-dependencies 1.13.0 and similar) no longer fail during PackageInfo decoding of target build settings. Tuist mirrors SwiftPM’s lowering into Xcode flags: OTHER_SWIFT_FLAGS gets -warnings-as-errors / -no-warnings-as-errors and -Werror <name> / -Wwarning <name>, while OTHER_CFLAGS / OTHER_CPLUSPLUSFLAGS get -Werror / -Wno-error, -Werror=<name> / -Wno-error=<name>, and -W<name>, preserving the warning behavior the package author configured.