Level optimization

[getkey]

Sometimes levels can contain long numbers, probably because of floating point issues. It increases the size of levels while not adding any useful information.

Example from [luw4n on Discord](https://discord.com/channels/526188679006388254/681629693501243393/863836754905268264)

		{
			"type": "deadly",
			"params": {
				"isStatic": true,
				"vertices": [
					{
						"x": 300,
						"y": -88.00000000000001
					},
					{
						"x": 300,
						"y": -89.00000000000001
					},
					{
						"x": 290,
						"y": -109.00000000000001
					},
					{
						"x": 280,
						"y": -89.00000000000001
					},
					{
						"x": 270,
						"y": -109.00000000000001
					},
					{
						"x": 260,
						"y": -89.00000000000001
					},
					{
						"x": 250.00000000000003,
						"y": -109.00000000000001
					},
					{
						"x": 240.00000000000003,
						"y": -89.00000000000001
					}

It would be great if the levels could be optimized, either:

• automatically in the editor after each edition
• automatically in the editor on upload
• manually in the editor (a button that asks the precision you need?)
• automatically by the backend

I'm not sure what's the best option for now, so tracking that here. I've added the functionality to BLT: getkey/bombhopperio-level-tools@e0134d8, which should be useful whatever the decision.