Fix OOB access in math.Vector swizzle; add '0' and '1' swizzles

[lordmauve]

Fixes #2023.

This adds bounds checks on swizzles like Vector2().xyz.

What I actually dived into this code for was to add swizzles with the digits 0 and 1. I can't easily make the two changes independent now so it's one PR.

>>> Vector2(3, 2).xy1
Vector3(3, 2, 1) 
>>> Vector2(3, 2).xy01
(3, 2, 0, 1) 

These will be useful to prepare homogenous coordinates for affine transforms by matrix multiplication. Here is a matrix representing a 2x scale + (3, -1) translation:

>>> import numpy as np
>>> from pygame.math import Vector2
>>> v = Vector2(0.5, 0.8)
>>> mat = np.array([
...   [2, 0, 3],
...   [0, 2, -1],
... ])
>>> mat @ v.xy1
array([4. , 0.6])

Given that the intended usage would be .xy1, .xyz1 or .xy01, it's not really a disadvantage that we can't syntactically write .10yx or something strange.

[MyreMylar]

This all seems to make sense to me.

Will leave it up for awhile in case anyone else has any feedback before merging.