Implement Conway's Game of Life

What does this MR do?

This MR implements Conway's game of life.

Double-check

• Reflect and resolve the CopyMeGrid improvement suggestions.

Can this MR be accepted?

• Implemented / improved the model
• Added or adapted model tests
  • Python tests
  • C++ tests (optional)
  • Added model to test:models job in .gitlab-ci.yml
  • Checked test code coverage on new and adjusted code
• Implemented plotting functions
• Added documentation
  • Model itself is reasonably well documented
  • Model description in doc/models/ (.rst format!)
• Model requirements (see documentation) are all fulfilled
• Reasonably up-to-date with current master
• Pipeline passing without warnings
• Squash option set or history cleaned-up
• Approved by @blsqr