Refactor fade system

[FlashyReese]

Refactor Summary

In this refactor, several changes have been made to improve the game's blending and transition systems.

• Altered blend modes and removed darken and lighten blend modes, which were causing issues in the game. A custom blend equation functionality has been implemented to set the shader color with an alpha channel of 1.0F.
• The alpha calculation has been moved from the render thread to the main thread. This will help ensure consistent transition durations, as previously, the calculation done on the render thread led to varying durations depending on FPS.
• The fade system has been improved to properly use the transitionSpeed property for alwaysOn skyboxes and to respect the maxAlpha value, which was previously not always being respected and set to 1.0F.
• Finally, the transitionSpeed property has been removed in favor of transitionInDuration and transitionOutDuration, which now take the duration in ticks instead.

Breaking Changes

Please be aware that these changes will break resource packs that have used the transitionSpeed property. The default fade transition speed has been set to 20 ticks (1 second) for such resource packs that now use transitionInDuration and transitionOutDuration. The change also breaks resource packs that used the blend modes darken and lighten.

Motivation

The motivation behind these changes is to improve the precision of transition durations and to resolve issues with blending and transition systems in the game. By using transitionInDuration and transitionOutDuration, more control can be exercised over the transition durations. Additionally, moving the alpha calculation to the main thread and improving the fade system will help ensure that transitions occur consistently and properly respect the maxAlpha value.

[FlashyReese]

This PR still requires a bit of testing before it can be merged.

[FlashyReese]

This latest commit replaces the transitionSpeed property with transitionInDuration and transitionOutDuration which are now in ticks for ultimate precision! Just a friendly reminder, some resource packs that were using transitionSpeed may have trouble, but don't worry, we made sure the default fade transition speed is set to 20 ticks (1 second) for them. The reason for this change was to make things even more precise and avoid any unhappy accidents from the previous property.