* Add KNOWN_PROXIES
* Add known proxy setup in Startup.cs
Refactor forwarded headers configuration to use a variable for options.
* Document KNOWN_PROXIES in .env file
Added documentation for KNOWN_PROXIES environment variable
* Clean up
Restored license comments and formatting in Constants.cs.
* Apply suggestion from @thecodrr
* Added KnownProxies functionality at Streetwriters.Common level
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Co-authored-by: Abdullah Atta <thecodrr@protonmail.com>