Transparency of Hud

[lonefelidae16]

Hi 👋

Thank you for the nice GUI improvements for Hud transparency and Tooltips.

I was able to work on an enhancement that has been on my mind a bit for a while, so let me share my code.

• When a Hotbar item is changed repeatedly while Hud is fading out, the fade-in is restarted from the beginning each time
• Tooltip background color changes at once regardless of the text alpha

https://user-images.githubusercontent.com/74746227/229699194-8cb6735c-cd43-4af5-b3b7-a030091eb13c.mp4

^{Above: new, Below: current implementation}

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The Hud Opacity functionality now can also be applied to block items.

I will create a new PR of this.