[4.0] Styling improvements for com_config (site)

[C-Lodder]

Pull Request for Issue # .

Summary of Changes

This PR fixes a few styling issues for Global Configurations in the frontend.

Testing Instructions

1. Save/cancel buttons are styled correctly.
2. Ensure the grid is aligned correctly.

[brianteeman]

The two column layout is still unusable

[C-Lodder]

Try now

[ghost]

I have tested this item ✅ successfully on 43aaaa0

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/19230.}

[brianteeman]

I have tested this item ✅ successfully on 43aaaa0

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/19230.}

[ghost]

Ready to Commit after two successful tests.

[wilsonge]

Thanks guys :)