Read HTTP_PORTS and HTTPS_PORTS into IServerAddresses

[Tratcher]

Fixes #43135

Container images want to be able to specify ports rather than urls. We want to avoid overloading the definition for ASPNETCORE_URLS, so this adds support for ASPNETCORE_HTTP_PORTS and ASPNETCORE_HTTPS_PORTS. URLS still takes priority, these new variables will be ignored if URLS is set.

Each is a list of semi-colon delimited values that will be mapped to http(s)://*:{port} respectively.

This will cause Kestrel to bind to all public IPs with IPv4 and IPv6 for the given ports.

This would also work with Http.Sys though we have a warning there not to use wildcards.
https://learn.microsoft.com/en-us/aspnet/core/fundamentals/servers/httpsys?view=aspnetcore-6.0#configure-windows-server

This is only implemented for generic web host and newer, not legacy webhost.

[halter73]

Can we log a warning if we ignore HTTP_PORTS and/or HTTPS_PORTS becuase URLS is set?

[Tratcher]

warn: Microsoft.AspNetCore.Hosting.Diagnostics[15]
      Overriding HTTP_PORTS '5002' and HTTPS_PORTS ''. Binding to values defined by URLS instead 'http://*:5003'.
warn: Microsoft.AspNetCore.Server.Kestrel[0]
      Overriding address(es) 'http://*:5003'. Binding to endpoints defined via IConfiguration and/or UseKestrel() instead.
info: Microsoft.Hosting.Lifetime[14]
      Now listening on: http://[::]:5004

[davidfowl]

Lots of warnings.......... 😄

[ghost]

@Tratcher, this change will be considered for inclusion in the blog post for the release it'll ship in. Nice work!

Please ensure that the original comment in this thread contains a clear explanation of what the change does, why it's important (what problem does it solve?), and, if relevant, include things like code samples and/or performance numbers.

This content may not be exactly what goes into the blog post, but it will help the team putting together the announcement.

Thanks!