Rework the tests by splitting them into traditional unit tests and exhaustive performance tests #8
Description
The idea is to improve the test readability and the speed of writing unit tests. The unit tests would be mandatory for each algorithm/data structure, whereas the performance test could be provided later (or be mandatory only for critical code from the solutions).
The exhaustive tests could be further improved by incorporating more advanced methods for generating random inputs. Speed shouldn't be a concern in performance tests, as they will be executed occasionally. For this reason, they ideally should reside in a different package and not be a part of the testing phase in the CI workflow.