SwissArmyLib v1.21.1

Updated Unity .dlls to 2022.3.6f1 LTS

SwissArmyLib v1.19.2

• Target .Net Framework version updated to 4.8 for latest versions of Unity and more compatibility across platforms and C# versions.
• Removed WaitForWWW as WWW is obsolete and implemented WaitForWebRequest instead which returns an AsyncOperation object to be used in the coroutine.
• Updated Unity .dll files to Unity 2022.3.5 LTS
• Updated NUnit and NUnit Test Adapter packages to the latest stable releases from Nuget
• Updated SandCastle package related issues and FrameWork version on Documentation area

TODO:
Update documentation.