Refactor/sidebar

[BrettCleary]

sidebar elements are now centered correctly.

before

after

Also applied some of the .button style to the button element. Applying other fields breaks some of the existing design.

Renamed some of the styles to match the style-xx naming convention.

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Use the following Checklist if you have changed something on the Backend or Frontend:

• Tested the feature and it's working on a current and clean install.
• Tested the main App features and they are still working on a current and clean install. (Login, Install, Play, Uninstall, Move games, etc.)
• Created / Updated Tests (If necessary)
• Created / Updated documentation (If necessary)

[CommandMC]

I can't really review this change as I have little CSS knowledge, but from the provided images & small bit of testing myself, seems to be alright 👍