Render block overlay fix based on state

[jchung01]

The block overlay fix was being called on any call to RenderGlobal#renderBlockLayer(), which may include other mods (i.e. Portal Gun) that render the world again in the same pass. So a solution is to use a flag to only call the block overlay fix exactly where we want to. Fixes #549.

[what-the-diff]

PR Summary

• Introduction of New Method and Fields in UTBlockOverlay.java
  A new method along with two boolean fields was added to the UTBlockOverlay.java file. This enhancement allows us to add extra functionalities and improve the logic of our codebase.

• Refactor of UTBlockOverlayMixin.java
  We've made modifications to the UTBlockOverlayMixin.java file which includes renaming methods and revising condition checks. Refactoring helps to simplify the code, making it easier to understand, manage, and modify in the future.

• Creation of New File: UTEntityRendererMixin.java
  A new file named UTEntityRendererMixin.java has been created. This file allows us to implement specific functionalities related to rendering entities within our application.

• Update in JSON File
  The mixins.bugfixes.blocks.blockoverlay.json file has been updated to include the newly created UTEntityRendererMixin.java class, enabling us to use its functionalities and cater to bug fixes associated with block overlays in an efficient manner.