Implement share/activity button on iOS

Multiplatform/iOS/Article/FindInArticleActivity.swift

@@ -0,0 +1,40 @@
+//
+//  FindInArticleActivity.swift
+//  NetNewsWire-iOS
+//
+//  Created by Brian Sanders on 5/7/20.
+//  Copyright © 2020 Ranchero Software. All rights reserved.
+//
+
+import UIKit
+
+class FindInArticleActivity: UIActivity {
+	override var activityTitle: String? {
+		NSLocalizedString("Find in Article", comment: "Find in Article")
+	}
+	
+	override var activityType: UIActivity.ActivityType? {
+		UIActivity.ActivityType(rawValue: "com.ranchero.NetNewsWire.find")
+	}
+	
+	override var activityImage: UIImage? {
+		UIImage(systemName: "magnifyingglass", withConfiguration: UIImage.SymbolConfiguration(pointSize: 20, weight: .regular))
+	}
+	
+	override class var activityCategory: UIActivity.Category {
+		.action
+	}
+	
+	override func canPerform(withActivityItems activityItems: [Any]) -> Bool {
+		true
+	}
+	
+	override func prepare(withActivityItems activityItems: [Any]) {
+		
+	}
+	
+	override func perform() {
+		NotificationCenter.default.post(Notification(name: .FindInArticle))
+		activityDidFinish(true)
+	}
+}