[Swift] Implements FlatbuffersVector which confirms to RandomAccessCollection (#8752)

* Implements FlatbuffersVector in swift

Implements FlatbuffersVector which confirms to RandomAccessCollection,
this would give us semi-native sugary syntax to all the arrays in swift port.

This work will also be the foundation of using arrays in swift

* Fix failing tests for Swift

swift/Sources/FlatBuffers/Message.swift

@@ -28,20 +28,20 @@ public protocol FlatBufferGRPCMessage {
   @inline(__always)
   func withUnsafeReadableBytes<T>(
     _ body: (UnsafeRawBufferPointer) throws
-      -> T
-  ) rethrows -> T
+      -> T) rethrows -> T
 }
 
 /// Message is a wrapper around Buffers to to able to send Flatbuffers `Buffers` through the
 /// GRPC library
-public struct Message<T: FlatBufferObject>: FlatBufferGRPCMessage {
+public struct Message<T: FlatBufferTable>: FlatBufferGRPCMessage {
   internal var buffer: ByteBuffer
 
   /// Returns the an object of type T that would be  read from the buffer
   public var object: T {
     T.init(
       buffer,
-      o: Int32(buffer.read(def: UOffset.self, position: buffer.reader)) &+ Int32(buffer.reader))
+      o: Int32(buffer.read(def: UOffset.self, position: buffer.reader)) &+
+        Int32(buffer.reader))
   }
 
   public var size: Int { Int(buffer.size) }
@@ -66,8 +66,8 @@ public struct Message<T: FlatBufferObject>: FlatBufferGRPCMessage {
   @inline(__always)
   public func withUnsafeReadableBytes<Data>(
     _ body: (UnsafeRawBufferPointer) throws
-      -> Data
-  ) rethrows -> Data {
+      -> Data) rethrows -> Data
+  {
     return try buffer.readWithUnsafeRawPointer(position: buffer.reader) {
       try body(UnsafeRawBufferPointer(start: $0, count: size))
     }