Nav: rectangle highlight not rendered for items with ImGuiItemFlags_NoNav. (#8057)

Not fully honored in ItemHoverable/IsItemHovered, seems more destructive. This is mostly designed to avoid rectangle being rendered by large InvisibleButton() when ctrl+tabbing back to a window with a big one.

docs/CHANGELOG.txt

@@ -72,6 +72,8 @@ Other changes:
   back into same window later.
 - Nav: fixed Ctrl+Tab so when starting with no focused window it starts from the top-most
   window. (#3200)
+- Nav: rectangle highlight not rendered for items with ImGuiItemFlags_NoNav. Can be relevant
+  when e.g activating the item with mouse, then ctrl+tabbing back and forth. 
 - DrawList: AddCallback() added an optional size parameter allowing to copy and
   store any amount of user data for usage by callbacks: (#6969, #4770, #7665)
   - If userdata_size == 0: we copy/store the 'userdata' argument as-is (existing behavior).

imgui.cpp

@@ -3701,6 +3701,8 @@ void ImGui::RenderNavHighlight(const ImRect& bb, ImGuiID id, ImGuiNavHighlightFl
         return;
     if (g.NavDisableHighlight && !(flags & ImGuiNavHighlightFlags_AlwaysDraw))
         return;
+    if (id == g.LastItemData.ID && (g.LastItemData.InFlags & ImGuiItemFlags_NoNav))
+        return;
     ImGuiWindow* window = g.CurrentWindow;
     if (window->DC.NavHideHighlightOneFrame)
         return;