Fixed bug in GridContainer with hidden children

[besh81]

Fix a bug that occour when there are hidden children in grid_container.
The visualization isn't correct due to a wrong calculation of max_col and max_row that mistakenly includes hidden children.

[KoBeWi]

Can you provide some minimal project that reproduces the bug? (is there maybe issue open about it?)
Also you need to run clang-format.

[besh81]

I didn't find any issue in the tracker.

Here a simple project that reproduce the bug:
bug_grid_container.zip

Screenshot:

As you can see in the second grid_container there is an empty space at the bottom due to the hidden children that shouldn't be there.
The second grid_container should be exactly like the first.

[KoBeWi]

Needs squash.

[YuriSizov]

@besh81 Please squash commits, so we can merge this approved fix 🙂
If you need help with squashing, you can refer to this guide from the Godot documentation (or any article about squashing in Git, really).

[besh81]

After several attempts I think I did my first "squash" correctly or I hope so 😄
Please let me know if ok

[akien-mga]

Thanks!