feat: remove explicit literals

[ImkoMarijnissen]

TODOS

• [x] compute_new and all the others should be removed or refactored
• [x] There used to be an option for turning off clause-minimisation
• [x] TODOs in conflict analysis
• [x] Restore test cases in constraint satisfaction solver
• [x] Proof logging
• [x] Core extraction
• [x] get_conflict_info now clones but should not
• [x] Doc tests
• [x] Refactor get_reason_simple
• [x] Check python interface
• [x] Remove the backtracking method from conflict analysis context
• [ ] The semantic minimiser does not take into account root-level holes in the domain

Issues:

• Closes https://github.com/ConSol-Lab/Pumpkin/issues/116
• Closes https://github.com/ConSol-Lab/Pumpkin/issues/81
• Closes https://github.com/ConSol-Lab/Pumpkin/issues/25
• Closes https://github.com/ConSol-Lab/Pumpkin/issues/3