[Swift language features] Implement Swift enums in C#

[kotlarmilos]

Tasks

• [SwiftBindings] Extra enum-specific entries in ValueWitnessTable #2881
• [Swift language features] Implement Swift wrappers for enums #2836
• Add Dynamo emitter for non-linear code generation
• Project trivial Swift enum into C# struct/class
• Project trivial Swift enum with methods into C# struct/class
• Project homogeneous Swift enum into C# struct/class
• Project heterogeneous Swift enum into C# struct/class