[FEATURE] Hover on buttons show preview of button post-click state

[KieranBond]

• Is your feature request related to a problem? Please describe.

When hovering on buttons currently, it's very ugly. It fills the 'block' that the buttons icon consists of with a semi-transparent white.

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• Describe the solution you'd like

Instead of showing this block of white, show what the icon would look like post-click. For example, when hovering over the Pause button make it appear as the Play button.

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• Describe alternatives you've considered

Another alternative to showing the post-click state would be to just remove any on hover behaviors, and just allow the mouse to appear as the clicking hand icon instead.