Add conceptual docs on accessing HttpContext

[mikekistler]

This PR adds docs and sample to describe how to access the HttpContext for a request from a tool call handler.

[Copilot]

Pull Request Overview

This PR adds comprehensive documentation and sample code demonstrating how to access HttpContext from MCP tool call handlers when using the HTTP transport. The documentation includes explanations of using IHttpContextAccessor, code snippets, and working examples.

Key changes:

• Adds new HttpContext concept documentation with examples
• Creates sample project showing HttpContext access patterns in tool handlers
• Updates project files to disable assembly info generation across samples

Reviewed Changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
docs/concepts/toc.yml	Adds HTTP Context section to documentation table of contents
docs/concepts/httpcontext/httpcontext.md	Main documentation explaining HttpContext access patterns
docs/concepts/httpcontext/samples/	Complete sample project demonstrating HttpContext usage
Multiple .csproj files	Adds assembly info generation settings to maintain consistency
ModelContextProtocol.slnx	Includes new HttpContext sample project in solution

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[eiriktsarpalis]

Thanks.