Prompt user when inviting users with uncached identities (#5331)

If the user attempts to invite someone (to a room or creating a DM) whose identity is not cached, we prompt them to make sure this was their intention.

PreviewTests/Sources/GeneratedPreviewTests.swift

@@ -475,6 +475,14 @@ extension PreviewTests {
         }
     }
 
+    @Test
+    func inviteUsersConfirmationSheetView() async throws {
+        AppSettings.resetAllSettings() // Ensure this test's previews start with fresh settings.
+        for (index, preview) in InviteUsersConfirmationSheetView_Previews._allPreviews.enumerated() {
+            try await assertSnapshots(matching: preview, step: index)
+        }
+    }
+
     @Test
     func inviteUsersScreenSelectedItem() async throws {
         AppSettings.resetAllSettings() // Ensure this test's previews start with fresh settings.