Update license from MIT to EUPL v. 1.2

[RoelvandenBerg]

Replaced MIT License with European Union Public Licence v. 1.2, detailing terms and conditions for use, modification, and distribution of the work.

Description

What have you changed and why?

Type of change

(Remove irrelevant options)

• Minor change (typo, formatting, version bump)
• New feature
• Improvement of existing feature
• Bugfix
• Refactoring
• Configuration change
• Breaking change

Checklist:

• I've double-checked the code in this PR myself
• I've left the code better than before (boy scout rule)
• The code is readable, comments are added that explain hard or non-obvious parts.
• I've expanded/improved the (unit) tests, when applicable
• I've run (unit) tests that prove my solution works
• There's no sensitive information like credentials in my PR