Fix tab movement while running multiple actions (#11144)

## Summary of the Pull Request
Make sure to always synchronously set the selected tab. This way when changing tabs while running multiple actions further calls to _GetFocusedTab will return the correct one.

**Edit** #11146  discovered while trying to test this so while I fixed the case I wanted, things seem to be broken generally so it is hard for me to test if I broke anything else.

## References

## PR Checklist
* [x] Closes #11107 
* [x] CLA signed. If not, go over [here](https://cla.opensource.microsoft.com/microsoft/Terminal) and sign the CLA

## Validation Steps Performed
Ran the command specified in the issue and confirmed that the correct tab was focused and that the correct pane was zoomed.

src/cascadia/TerminalApp/TabManagement.cpp

@@ -599,9 +599,13 @@ namespace winrt::TerminalApp::implementation
         tabIndex = std::clamp(tabIndex, 0u, _tabs.Size() - 1);
 
         auto tab{ _tabs.GetAt(tabIndex) };
+        // GH#11107 - Always just set the item directly first so that if
+        // tab movement is done as part of multiple actions following calls
+        // to _GetFocusedTab will return the correct tab.
+        _tabView.SelectedItem(tab.TabViewItem());
+
         if (_startupState == StartupState::InStartup)
         {
-            _tabView.SelectedItem(tab.TabViewItem());
             _UpdatedSelectedTab(tab);
         }
         else