messages: open web links in full web browser

In [1], all hyperlinks within `MessagesNode` switched to using

    activity.openUrlInChromeCustomTab()

instead of with `openUrlInExternalApp()`.

This causes web links in chat messages to open in an "in-app"
Chrome Custom Tab [2] instead of the user's configured "full"
web browser. This is a UX nuisance. Open web links in a full
browser instead.

Closes #3885 [3].

[1]: 57e45aa834 (Identity change: handle click on "learn more")

[2]: https://developer.chrome.com/docs/android/custom-tabs/guide-get-started#opening_a_custom_tab

[3]: https://github.com/element-hq/element-x-android/issues/3885

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/MessagesNode.kt

@@ -40,6 +40,7 @@ import io.element.android.features.messages.impl.timeline.di.LocalTimelineItemPr
 import io.element.android.features.messages.impl.timeline.di.TimelineItemPresenterFactories
 import io.element.android.features.messages.impl.timeline.model.TimelineItem
 import io.element.android.libraries.androidutils.browser.openUrlInChromeCustomTab
+import io.element.android.libraries.androidutils.system.openUrlInExternalApp
 import io.element.android.libraries.androidutils.system.toast
 import io.element.android.libraries.architecture.NodeInputs
 import io.element.android.libraries.architecture.inputs
@@ -148,7 +149,9 @@ class MessagesNode @AssistedInject constructor(
             is PermalinkData.RoomLink -> {
                 handleRoomLinkClick(activity, permalink, eventSink)
             }
-            is PermalinkData.FallbackLink,
+            is PermalinkData.FallbackLink -> {
+                activity.openUrlInExternalApp(url)
+            }
             is PermalinkData.RoomEmailInviteLink -> {
                 activity.openUrlInChromeCustomTab(null, darkTheme, url)
             }