Add SpriteStep Object

[ellestuff]

Sprite Steps let you draw directly to sprites via canvases. This additionally allows for shader stacking and more

Example:

	SMODS.SpriteStep {
		key = "burns",
		order = 1,
		func = function(self, image, quad, sprite)
			love.graphics.setShader(burn_shader)

			local w,h = quad:getTextureDimensions()
			local sw,sh = quad:getViewport()

			burn_shader:send("offset", {w,h,sw,sh})
			burn_shader:send("seed", sprite.parent.unique_val)
			burn_shader:send("amp", sprite.parent.ability.elle_burn_effect)
		
			love.graphics.draw(image,quad,0,0)
		end,
		should_apply = function(self, sprite)
			return sprite.parent and sprite.parent.ability and sprite.parent.ability.elle_burn_effect and sprite.parent.ability.elle_burn_effect > 0
		end
	}

Additional Info:

• I didn't modify api's or I've made a PR to the wiki repo.
• I didn't modify api's or I've updated lsp definitions.
• I didn't make new lovely files or all new lovely files have appropriate priority.

[ellestuff]

don't merge this yet, i've found it out doesn't work when pixel smoothing is on. i need to fix that first

[ellestuff]

okay it's fixed now, it wasn't a bug with pixel smoothing but rather something else