Merge pull request #73 from SPauly/feat68

Closes #68

Merge pull request #62 from SPauly/development

Feature: Buy A Book: Closes #57

Merge pull request #60 from SPauly/bug58

Changed DTOR in User: Closes #58

Merge pull request #55 from SPauly/development

Closes #52

Merge pull request #46 from SPauly/feat44

Close #44

Merge branch 'main' of https://github.com/SPauly/Library-Simulation-M…

…anagement-System into main

bugfix