Add swift language support for ios and macos

[AGulev]

[ekharkunov]

What exactly are you expecting here? Extender can compile extensions with Swift code (some cocoapods dependencies have swift code).

[britzl]

The expectation is to be able to include swift files in your own extension code and have it compile on the extender server just like we do with ObjC code.

[britzl]

We should try to move towards a "vanilla" build experience on extender to build with xcode, instead of the current Frankenstein solution we have now.