feat: adding new rust plugin sample - mcp translation

[pweiber]

Translate a request to be in a MCP format

Agent -> LB (transform to MCP via Service Extension) -> (MCP compliant) Toll and back again.

MCP Context: https://www.anthropic.com/news/model-context-protocol

MCP Specification: https://modelcontextprotocol.io/specification/2025-03-26

Includes changes to the test framework to address some of the issues that I was having with immediate responses and body

Includes minor test changes for docs_plugin_config

Note: Saw an issue with the tests for the new recaptcha plugin due to the changes, currently checking it

[snippet-bot]

Here is the summary of changes.

You are about to add 1 region tag.

• plugins/samples/mcp_translation/plugin.rs:15, tag serviceextensions_plugin_mcp_translation

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