[Tracking] Kestrel config asks

[analogrelay]

Here are things we expect to need expanded on for kestrel's existing config system:

• Endpoint config reload: Kestrel reloadable config aspnetcore#19376
• Backpressure: Rate Limit for Kestrel - Design mechanism to apply back pressure to accepting connections aspnetcore#13295
  • Planned for 6.0
• [EPIC] HTTPS and Certificate Handling in Kestrel: [EPIC]: HTTPS and Certificate Handling in Kestrel aspnetcore#21512
  • SNI config: Support SNI via config aspnetcore#15144 (Working)
    • Tracked individually by SNI cert selection support #86
    • In 5.0.0-preview8 milestone
  • Client cert mode: Setting the ClientCertificateMode Kestrel server option from an appsettings.json file. aspnetcore#18660
  • PEM certs: Add support for PEM format SSL certificates aspnetcore#4706
    • PR open by @javiercn: [HTTPS] Adds PEM support for Kestrel aspnetcore#23584

[karelz]

Triage: All covered.