Add the intent system back to call widget URL creation. (#4511)

Add the intent system back to widget URL creation.

Also updates the SDK handling API changes.

UnitTests/Sources/RoomTests.swift

@@ -0,0 +1,34 @@
+//
+// 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 MatrixRustSDK
+import XCTest
+
+@testable import ElementX
+
+class RoomTests: XCTestCase {
+    func testCallIntent() async throws {
+        let room = RoomSDKMock()
+        room.hasActiveRoomCallReturnValue = false
+        room.isDirectReturnValue = false
+        
+        var callIntent = await room.joinCallIntent
+        XCTAssertEqual(callIntent, .startCall)
+        
+        room.isDirectReturnValue = true
+        callIntent = await room.joinCallIntent
+        XCTAssertEqual(callIntent, .startCallDm)
+        
+        room.hasActiveRoomCallReturnValue = true
+        callIntent = await room.joinCallIntent
+        XCTAssertEqual(callIntent, .joinExistingDm)
+        
+        room.isDirectReturnValue = false
+        callIntent = await room.joinCallIntent
+        XCTAssertEqual(callIntent, .joinExisting)
+    }
+}