fix(chat): adding new events for list mcp server and click mcp events. (aws#7314)

## Problem
We need to catch MCP server menu events on VSCode.

## Solution
- Updated runtimes for new VSCode requests for mcp servers.
- Added switch cases for mcp events.

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Author: ashishrp-aws