A way to change the texture for GUI buttons

Issue description

It is possible to make custom backgrounds for GUIs and slots but its not possible to change the texture of the button due to no file or texture we have access to to edit in an image file.

Could we please have support for changing the way buttons look in our GUI even if its just support for texturing the button itself so we can make it match the rest of the GUI.

Here is an example:

GUI with vanilla button texture.

Minecraft beacon buttons are below the GUI image.
Beacon Texture With Buttons

Even if we got a seperate file with just elements for our GUI like buttons, images, and text boxes it would help customize our GUI's a bit more.

Issue comments

This one is a bit tougher but possible and in scope somehow. I will consider this down the road.

Was not this feature already planned?

My bad. I thought he meant buttons with a custom picture (like the arrows inside the book).

Yes, this is another thing and much easier. Such buttons (normal button with icon) are currently targeted for 2020.4.

2020.4 is almost released, is this delayed to to 2020.5(+)?

Pre-releases have locked feature list to not introduce new bugs

And now?

Migrated to https://github.com/MCreator/MCreator/issues/114

I would love to have this feature. The default buttons clash with my pastel GUI's and I want an easy way to modify them

Yeah, I've been looking for a way to change this for a long time. Or at the very least, I want a way to remove the gray box around the text of the button, but still make the text clickable.