remove print from public API

[tomerd]

motivation: reduce public API surface area given the plan is to abosrb this library in the language runtime eventually

changes:

• make print function private
• remove explicit swift-server file

[tomerd]

as discussed on our last sswg call, removing print to reduce API surface area. will need a major version bump I assume

[weissi]

@tomerd yes, will need a major bump. There's one thing we could do instead: We could just deprecate it in a minor for now??

[tomerd]

We could just deprecate it in a minor for now??

works for me

@ianpartridge @tanner0101 ?