Profile HTTP/2 and identify hotspots

[shirhatti]

Scenarios:

• TechEmpower plaintext but over HTTP/2
• Basic POST. Request is text/plain string of name. Reply is text/plain "Hello " + name
• Basic gRPC. See gRPC tutorial
• Streaming gRPC. The same as the basic gRPC but the server streaming multiple messages
• Stream per connection vs multiple streams on one connection
• H2 vs H2C
• Kestrel and IIS HTTP/2 performance
• Server streaming

Output:

• Create new HTTP2 issues with screenshots/traces/numbers from profile

[davidfowl]

This is an old benchmark from preview4 #6567

[jkotalik]

@JamesNK is #13752 sufficient for the info covered here?