**Only one functional change**
* Fixes a bug in LogFactory where `Warning` is being logged as `Information`
Non-functional changes:
* Updates/Fixes copyright headers
* Removes namespace scopes for core files.
View with [whitespace off](https://github.com/modernuo/ModernUO/pull/1187/files?w=1).
* Fixes an issue with moving directories across volumes
* Removes usages of WebClient
* Removes usages of Cryptographic Providers
Note: Even though .NET 6 introduces Xoshiro RNG, there is no way to control the seed. I'll do some reconciliation of Xoshiro so it functions closer to the built in one. For the most part, it has parity though.
Benchmarks show there is nothing odd about the implementations, they are within 1ns of each other.
