Force Omni Bar cancellation when submitting a query (#2923)

Task/Issue URL: https://app.asana.com/0/414709148257752/1207493955850425/f
Tech Design URL:
CC:

Description:

This PR updates the omni bar query submitted callback to cancel the omni bar, to ensure it stays in the correct state.

This bug is caused by MainViewController.onEditingEnd(), which gets checked before the autocomplete controller has been torn down. This puts the omni bar into a suspended state, not dismissed state.

DuckDuckGo/MainViewController.swift

@@ -1714,6 +1714,7 @@ extension MainViewController: OmniBarDelegate {
         if !DaxDialogs.shared.shouldShowFireButtonPulse {
             ViewHighlighter.hideAll()
         }
+        omniBar.cancel()
         loadQuery(query)
         hideSuggestionTray()
         hideNotificationBarIfBrokenSitePromptShown()