[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/Vectors/FlatbuffersVectorInitializable.swift

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2024 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import Foundation
+
+#if canImport(Common)
+import Common
+#endif
+
+public protocol FlatbuffersVectorInitializable {
+  static func readFrom(byteBuffer: ByteBuffer, index: Int) -> Self
+}
+
+extension Scalar where Self: FlatbuffersVectorInitializable {
+  public static func readFrom(byteBuffer: ByteBuffer, index: Int) -> Self {
+    byteBuffer.read(def: Self.self, position: index)
+  }
+}
+
+extension NativeStruct where Self: FlatbuffersVectorInitializable {
+  public static func readFrom(byteBuffer: ByteBuffer, index: Int) -> Self {
+    byteBuffer.read(def: Self.self, position: index)
+  }
+}
+
+extension FlatBufferStruct {
+  public static func readFrom(byteBuffer: ByteBuffer, index: Int) -> Self {
+    Self.init(byteBuffer, o: Int32(index))
+  }
+}
+
+extension FlatBufferTable {
+  public static func readFrom(byteBuffer: ByteBuffer, index: Int) -> Self {
+    return Self.init(
+      byteBuffer,
+      o: Int32(index) &+ byteBuffer.read(def: Int32.self, position: index))
+  }
+}
+
+extension Optional: FlatbuffersVectorInitializable where Wrapped == String {
+  public static func readFrom(byteBuffer: ByteBuffer, index: Int) -> Self {
+    var index = Int32(index)
+    index &+= byteBuffer.read(def: Int32.self, position: Int(index))
+    let count = byteBuffer.read(def: Int32.self, position: Int(index))
+    let position = Int(index) &+ MemoryLayout<Int32>.size
+    return byteBuffer.readString(at: position, count: Int(count))
+  }
+}
+
+extension Enum where Self: FlatbuffersVectorInitializable {
+  public static func readFrom(byteBuffer: ByteBuffer, index: Int) -> Self {
+    Self
+      .init(rawValue: byteBuffer.read(def: Self.T.self, position: index)) ??
+      Self.min
+  }
+}