Bridge `String(localized:bundle:)`

[piercifani]

Currently, String(localized:table:bundle:locale:comment:) is not bridged and we most fallback to NSLocalizedString.

It would be a nice addition to reduce the amount of changes needed to port existing iOS codebases.

[marcprux]

Note that for the short term, you could implement it yourself and forward the calls to NSLocalizedString. At least that way when we eventually implement String(localized:), you could just be able to remove your per-module override.

E.g.,

#if os(Android)
extension String {
    init(localized: String, bundle: Bundle, comment: String) {
        self = NSLocalizedString(…)
    }
}
#endif