`#bs.block:fill_pattern`: A function to fill an area with a pattern.

[SBtree-bit]

Given input pattern, a 2d/3d array of a pattern represented by numbers, and blocks, a mapping of numbers to blocks, this function could fill the area with the pattern of blocks. It could automatically repeat/crop the pattern to fit in the area as well. This would be useful in conjunction with #220, "Random Noise Texture Generation," which I am currently working on. The noise function could output a 2d array then used in this function to fill an area of blocks with a randomly generated pattern.