[MC-185156] Worldgen settings are not validated and can cause crashes

Some parameters are not validated and this can lead to a crash. This bug report is meant to list all those cases.

Parameter	Value	Result
`noise.size_horizontal` `noise.size_vertical`	0	Divide by zero [media]
`noise.size_horizontal` `noise.size_vertical`	~~< 0~~	~~Negative array size~~ [media]
`noise.height`	~~< 1~~	~~Bound must be positive~~ [media]
`noise.height`	~~> 256~~	~~Index out of bounds~~ [media]
`structures.*.spacing`	0	~~Divide by zero~~ [media]

Condition	Result
`structures.*.spacing` <= `separation`	~~Bound must be positive~~ [media]
`noise.height` < 9 and not a void biome	Bound must be positive [media]
Unknown (related to `spacing`)	String index out of range [media] Reproduce: [media]

Condition

Result

structures.*.spacing <= separation

~~Bound must be positive~~

[media]

noise.height < 9 and not a void biome

Bound must be positive

[media]

Unknown (related to spacing)

String index out of range

[media]

Reproduce: