iOS Swift Conversion (#2527)

Converts iOS implementation from Objective-c to Swift

# During the conversion process some updates to the code structure were also made
- Modularize codebase from single file to smaller focused files
- Untangled large nested IF statements
- Added more null checks, since Swift is more strict with null pointers
- Added property to allow for decoding of local video sources with self contained key for offline playback
- Updates example apps to test react-native 0.63.4 and uses auto native dependency imports for android and ios

examples/basic/tsconfig.json

@@ -1,20 +1,20 @@
 {
-    "compilerOptions": {
-      "allowJs": true,
-      "allowSyntheticDefaultImports": true,
-      "esModuleInterop": true,
-      "isolatedModules": true,
-      "jsx": "react-native",
-      "lib": ["es2017"],
-      "moduleResolution": "node",
-      "noEmit": true,
-      "strict": true,
-      "target": "esnext"
-    },
-    "exclude": [
-      "node_modules",
-      "babel.config.js",
-      "metro.config.js",
-      "jest.config.js"
-    ]
-  }
+  "compilerOptions": {
+    "allowJs": true,
+    "allowSyntheticDefaultImports": true,
+    "esModuleInterop": true,
+    "isolatedModules": true,
+    "jsx": "react-native",
+    "lib": ["es2017"],
+    "moduleResolution": "node",
+    "noEmit": true,
+    "strict": true,
+    "target": "esnext"
+  },
+  "exclude": [
+    "node_modules",
+    "babel.config.js",
+    "metro.config.js",
+    "jest.config.js"
+  ]
+}