Feature support Flutter 3.2.3 and include working example from earlier pull request

[sjhorn]

Related to

feat/add-example

Context

Updated swayze and swayze_math to support latest flutter (3.2.3) at the time.

Update unit tests for both and golden images.

Approach

Removed libraries and readied the latest started with flutter and test.

Fixed null-check issues and signature changes in swayze and swayze_math.

Then moves to have unit tests pass, most Goldens were within 0.8% and checking by eye could not see issues, so regenerated.

The mocking of DefaultSwayzeAction was having problems with its signature, so worked around using a manual mock and expect instead of verify for the problematic area.

Also a temporal issue with cell test, so adjusted to pumpWidget rather than pumpAndSettle and this removed the non-deterministic issue locally.

All same test now pass.