[QUIC] Implement MsQuicConfiguration cache

[rzikm]

On linux, creating the MsQuicConfiguration object is expensive because we need to export the X509Certificate in PKCS12 format. Doing this for each connection separately is a waste of resources. MsQuicConfiguration objects are designed to be shared between connections. We should look into implementing a configuration cache similar to what we have for SslStream on Windows.

Preliminary benchmarks suggest this should significantly reduce handshake time and thus time-to-first-byte and related metrics in HTTP/3.

Implementing a cache for the MsQuicConfiguration objects will allow us to also later implement TLS Session resumption, allowing even faster handshake.

[ghost]

Tagging subscribers to this area: @dotnet/ncl
See info in area-owners.md if you want to be subscribed.

Issue Details

---

On linux, creating the MsQuicConfiguration object is expensive because we need to export the X509Certificate in PKCS12 format. Doing this for each connection separately is a waste of resources. MsQuicConfiguration objects are designed to be shared between connections. We should look into implementing a configuration cache similar to what we have for SslStream on Windows.

Preliminary benchmarks suggest this should significantly reduce handshake time and thus time-to-first-byte and related metrics in HTTP/3.

Implementing a cache for the MsQuicConfiguration objects will allow us to also later implement TLS Session resumption, allowing even faster handshake.

Author:	rzikm
Assignees:	-
Labels:	tenet-performance, area-System.Net.Quic
Milestone:	-