feat: Implemented days of supply - backend

[BenjaminKotnik]

Description

• Implements days supply standard
• Days of Supply - Backend Implementation #309

Pre-review checks

Please ensure to do as many of the following checks as possible, before asking for committer review:

• DEPENDENCIES are up-to-date. Dash license tool. Committers can open IP issues for restricted libs.
• Copyright and license header are present on all affected files

[tom-rm-meyer-ISST]

Thanks for contributing. While reviewing I noticed the duplicate code we currently have in most of the object. I would prefer a refactoring prior to this PR so that we don't have that much duplication e.g., in methods like findAllByFilters. Same applies to new functionality to calculate days of supply which is the same calculation with different parameters.

Beside that:

• Please always wait for the pipeline to finish prior to requesting the review and check the findings. If you're not aware of what to do, please comment.
• Please add javadoc at least for the more complex functions. Normally also at least those should be tested.

[tom-rm-meyer-ISST]

Sorry misclick

[tom-rm-meyer-ISST]

Thanks for contributing and iterating over this with me! Highly appreciated. As we have more than 1kloc of code change, I filed an IP check at EF.

I will approve and merge as soon as the check succeeded.

Beside that: raised #454 to increase maintainability

[tom-rm-meyer-ISST]

IP check succeeded. Please merge main

[tom-rm-meyer-ISST]

LGTM, IP cleared. Thanks for contributing!