Don't capture HttpContext into the log objects

[benaadams]

Don't capture HttpContext into the log objects from #10319

Resolves #10556
Resolves #10557

/cc @davidfowl

[davidfowl]

Allocations!

[davidfowl]

I think this change is fine but there's no issue with console and other loggers that store messages in a queue for further processing (at least the ones that we ship). They materialize the message before en-queuing.

[benaadams]

there's no issue with console and other loggers that store messages

If you are happy with the current state, I'll close this as it does make HostingRequestStartingLog a bit bloaty

[neuecc]

@davidfowl @benaadams

The logger I'm developing has encountered this issue:
https://github.com/Cysharp/ZLogger

ZLogger adopts an architecture that consistently delays formatting and writes to an IBufferWriter<byte> to avoid allocating strings each time and for performance batching.
As a result, this logging, which captures the HttpContext, is causing problems:
Cysharp/ZLogger#165

Looking at the PR, it seems that incorporating this would solve the issue.
Is there still a possibility of reconsidering and merging this?

Also, I think it's bad to capture the HttpContext.
I were aware that the presence of such a capture could cause problems, but I did not believe that there was anything in the standard that would do such a behavior.