Fix rendering for some multisided blocks

[Arctcc]

Fixes rendering for blocks that have a top image and a side image. Doesn't fix blocks that have more than two images per block.

[TABmk]

Hi. First of all, thank you for contributing!
Maybe, we can save the renderSides option for rendering separate images for each sprite. Not sure that it can be useful, but it has already done.

I'll save the renderSides as is and move your code to the main render (without options).
I think no-options-render in the future must render blocks like in-game icons and we can move in this direction.

[TABmk]

Created a new branch atm, while I'm trying to understand how to move it outside renderSides