feat(analytics): Add Swift Package Manager (SPM) support

packages/mixpanel_flutter/ios/mixpanel_flutter.podspec

@@ -13,7 +13,7 @@ Pod::Spec.new do |s|
   s.license          = { :file => '../LICENSE' }
   s.author           = { 'Mixpanel, Inc' => 'support@mixpanel.com' }
   s.source           = { :path => '.' }
-  s.source_files = 'Classes/**/*'
+  s.source_files = 'mixpanel_flutter/Sources/mixpanel_flutter/**/*.swift'
   s.dependency 'Flutter'
   s.dependency 'Mixpanel-swift', '6.4.0'
   s.platform = :ios, '13.0'

packages/mixpanel_flutter/ios/mixpanel_flutter/Package.swift

@@ -0,0 +1,31 @@
+// swift-tools-version: 5.9
+import PackageDescription
+
+let package = Package(
+    name: "mixpanel_flutter",
+    platforms: [
+        .iOS("13.0")
+    ],
+    products: [
+        .library(
+            name: "mixpanel-flutter",
+            targets: ["mixpanel_flutter"]
+        )
+    ],
+    dependencies: [
+        .package(
+            url: "https://github.com/mixpanel/mixpanel-swift.git",
+            exact: "6.4.0"
+        )
+    ],
+    targets: [
+        .target(
+            name: "mixpanel_flutter",
+            dependencies: [
+                .product(name: "Mixpanel", package: "mixpanel-swift")
+            ],
+            path: "Sources/mixpanel_flutter",
+            resources: []
+        )
+    ]
+)

packages/mixpanel_flutter/ios/mixpanel_flutter/Sources/mixpanel_flutter/MixpanelTypeHandler.swift

@@ -0,0 +1 @@
+../../../../swift/Classes/MixpanelTypeHandler.swift

packages/mixpanel_flutter/ios/mixpanel_flutter/Sources/mixpanel_flutter/SwiftMixpanelFlutterPlugin.swift

@@ -0,0 +1 @@
+../../../../swift/Classes/SwiftMixpanelFlutterPlugin.swift

packages/mixpanel_flutter/swift/Classes/SwiftMixpanelFlutterPlugin.swift

@@ -9,6 +9,7 @@ import Mixpanel
 public typealias MixpanelFlutterPlugin = SwiftMixpanelFlutterPlugin
 #endif
 
+@objc(MixpanelFlutterPlugin)
 public class SwiftMixpanelFlutterPlugin: NSObject, FlutterPlugin {
 
     private var instance: MixpanelInstance?