All Projects updated to .NET 6, redundant code removed and old syntax…

[nirzaf]

… changed to new style

Description

All Projects updated to .NET 6, redundant code was removed and old syntax changed to the new style of syntax to adopt C# 10

Checklist

• [ x ] An issue was first created before opening this pull request
• [ x ] The new code follows the contribution guidelines
• [ x ] I have performed a self-review of my own code
• [ x ] I have commented my code, particularly in hard-to-understand areas
• [ x ] I have made corresponding changes to the documentation
• [ x ] My changes generate no new warnings
• [ x ] I have added tests to ensure that prove my fix is effective or that my feature works
• [ x ] New and existing unit tests pass locally with my changes