Allow creating XCFramework with debug symbols

[louwers]

Someone is asking if we can distribute our XCFramework with debug symbols (dSYMs) included. Apparently Apple allows you to upload XCFrameworks with dSYM included. Is this something that would be considered adding to apple_xcframework?

maplibre/maplibre-native#3155

[luispadron]

Yes, the upstream branch actually already has support: https://github.com/bazelbuild/rules_apple/blob/upstream/apple/internal/xcframework_rules.bzl#L470-L473

If you want to match that and make a PR we can review