Implement link previews for text messages using Apple's LinkPreview framework (#4520)

ElementX/Sources/Services/LinkMetadata/LinkMetadataProvider.swift

@@ -0,0 +1,27 @@
+//
+// Copyright 2025 New Vector Ltd.
+//
+// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+// Please see LICENSE files in the repository root for full details.
+//
+
+import LinkPresentation
+
+class LinkMetadataProvider: LinkMetadataProviderProtocol {
+    private(set) var metadataItems = [URL: LinkMetadataProviderItem]()
+    
+    func fetchMetadataFor(url: URL) async -> Result<LinkMetadataProviderItem, Error> {
+        if let item = metadataItems[url] {
+            return .success(item)
+        }
+        
+        do {
+            let metadata = try await LPMetadataProvider().startFetchingMetadata(for: url)
+            let item = LinkMetadataProviderItem(url: url, metadata: metadata)
+            metadataItems[url] = item
+            return .success(item)
+        } catch {
+            return .failure(error)
+        }
+    }
+}