Add permalink detection and custom attributed string attributes (#536)

* Pass full attributed string to TimelineItems and let the UI level handle blockquote coalescing
* Add permalink detection and attribute embedding within the attributed string

ElementX/Sources/Other/Extensions/AttributedString.swift

@@ -0,0 +1,37 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// 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
+
+extension AttributedString {
+    var formattedComponents: [AttributedStringBuilderComponent] {
+        runs[\.blockquote].map { value, range in
+            var attributedString = AttributedString(self[range])
+            
+            // Remove trailing new lines if any
+            if attributedString.characters.last?.isNewline ?? false,
+               let range = attributedString.range(of: "\n", options: .backwards, locale: nil) {
+                attributedString.removeSubrange(range)
+            }
+            
+            let isBlockquote = value != nil
+            /// This is a temporary workaround until replies are retrieved from the SDK.
+            let isReply = isBlockquote && attributedString.characters.starts(with: "In reply to @")
+            
+            return AttributedStringBuilderComponent(attributedString: attributedString, isBlockquote: isBlockquote, isReply: isReply)
+        }
+    }
+}