Add ts-jest testing config and adapt template

[C-Jansek]

It should be easily possible to add tests to the individual days.

This would help in writing better code faster. It would help to gain an overview of more complex days since you could test individual classes/methods.

This should also make it easier to de refactoring when the day is finished.

Installation ts-jest

How to install ts-jest is explained here: https://kulshekhar.github.io/ts-jest/docs/getting-started/installation/#jest-config-file

Adapting template

The default template should be adapted. This would mean:

• not executing the part1() and part2() methods when the template is imported in the tests.
• input as argument of the part1() and part2() methods, such that we can easily test the parts with different input

In addition to the default template, we should also generate a default test file from a template.

[C-Jansek]

This has already been done in one of the projects that uses this template, see https://github.com/C-Jansek/aoc-2023/pull/2