Fix perform move bug

[YoEnte]

Description

Fix: tiny but extremely breaking change in gamestate.perform_move(), where the carrots for pos1 and pos2 field have not been calculated correctly.
Add: gamestate.last_move to move.perform, was forgotten as "gamestate.last_move" got added.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How Has This Been Tested?

• With GUI Server on logs
• Test: New test for the fix, looks complicated, but it is basically a depth 2 calculation for the perform, with the options that the other player is in front or behind. Because of that I need to make changes to the test board in state_test.rs, but all other test still finish.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[maxblan]

lgtm