Refactor storage model to work with native Realm

ios/App/Shared/models/server/PodcastEpisode.swift

@@ -0,0 +1,72 @@
+//
+//  PodcastEpisode.swift
+//  App
+//
+//  Created by Ron Heft on 8/16/22.
+//
+
+import Foundation
+import RealmSwift
+
+class PodcastEpisode: EmbeddedObject, Codable {
+    @Persisted var id: String = ""
+    @Persisted var index: Int?
+    @Persisted var episode: String?
+    @Persisted var episodeType: String?
+    @Persisted var title: String = "Unknown"
+    @Persisted var subtitle: String?
+    @Persisted var desc: String?
+    @Persisted var audioFile: AudioFile?
+    @Persisted var audioTrack: AudioTrack?
+    @Persisted var duration: Double?
+    @Persisted var size: Int?
+    var serverEpisodeId: String { self.id }
+    
+    private enum CodingKeys : String, CodingKey {
+        case id,
+             index,
+             episode,
+             episodeType,
+             title,
+             subtitle,
+             desc = "description", // Fixes a collision with the base Swift object's field "description"
+             audioFile,
+             audioTrack,
+             duration,
+             size,
+             serverEpisodeId
+    }
+    
+    override init() {}
+    
+    required init(from decoder: Decoder) throws {
+        let values = try decoder.container(keyedBy: CodingKeys.self)
+        id = try values.decode(String.self, forKey: .id)
+        index = try? values.decode(Int.self, forKey: .index)
+        episode = try? values.decode(String.self, forKey: .episode)
+        episodeType = try? values.decode(String.self, forKey: .episodeType)
+        title = try values.decode(String.self, forKey: .title)
+        subtitle = try? values.decode(String.self, forKey: .subtitle)
+        desc = try? values.decode(String.self, forKey: .desc)
+        audioFile = try? values.decode(AudioFile.self, forKey: .audioFile)
+        audioTrack = try? values.decode(AudioTrack.self, forKey: .audioTrack)
+        duration = try? values.decode(Double.self, forKey: .duration)
+        size = try? values.decode(Int.self, forKey: .size)
+    }
+    
+    func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        try container.encode(id, forKey: .id)
+        try container.encode(index, forKey: .index)
+        try container.encode(episode, forKey: .episode)
+        try container.encode(episodeType, forKey: .episodeType)
+        try container.encode(title, forKey: .title)
+        try container.encode(subtitle, forKey: .subtitle)
+        try container.encode(desc, forKey: .desc)
+        try container.encode(audioFile, forKey: .audioFile)
+        try container.encode(audioTrack, forKey: .audioTrack)
+        try container.encode(duration, forKey: .duration)
+        try container.encode(size, forKey: .size)
+        try container.encode(serverEpisodeId, forKey: .serverEpisodeId)
+    }
+}