Implements verifier and code gen for swift (#6373)

Updates test cases on linux

Adhere to new protocol naming

Adds fuzzing

Adds documentation

Adds support for string unions

Updated fuzzer generated code

swift/Sources/FlatBuffers/FlatBufferObject.swift

@@ -31,15 +31,26 @@ public protocol FlatBufferObject: FlatbuffersInitializable {
   var __buffer: ByteBuffer! { get }
 }
 
+/// `ObjectAPIPacker` is a protocol that allows object to pack and unpack from a
+/// `NativeObject` to a flatbuffers Object and vice versa.
 public protocol ObjectAPIPacker {
+  /// associatedtype to the object that should be unpacked.
   associatedtype T
+
+  /// `pack` tries packs the variables of a native Object into the `ByteBuffer` by using
+  /// the FlatBufferBuilder
+  /// - Parameters:
+  ///   - builder: FlatBufferBuilder that will host incoming data
+  ///   - obj: Object of associatedtype to the current implementer
   static func pack(_ builder: inout FlatBufferBuilder, obj: inout T?) -> Offset
+
+  /// `pack` packs the variables of a native Object into the `ByteBuffer` by using
+  /// the FlatBufferBuilder
+  /// - Parameters:
+  ///   - builder: FlatBufferBuilder that will host incoming data
+  ///   - obj: Object of associatedtype to the current implementer
   static func pack(_ builder: inout FlatBufferBuilder, obj: inout T) -> Offset
+
+  /// `Unpack` unpacks a flatbuffers object into a `NativeObject`
   mutating func unpack() -> T
 }
-
-public protocol Enum {
-  associatedtype T: Scalar
-  static var byteSize: Int { get }
-  var value: T { get }
-}