Update all the demonstration of utilities to a test file

### Subject of the feature request
Fix all demonstration parts of the files in utilities folder to a test-specific file.

### Your environment
* **Scriptize version**: alpha
* **Terminal emulator**: ghostty
* **Shell**: zsh
* **Operating system**: Ubuntu 22.04

### More details
There are a lot of test that run the whole code in the demonstration section of almost all utilities files.
It would be better to move them to a specific test file. In addition, we can use tests in the functions docstrings.