Add configurable timeout for context server tool calls (#33348)

Closes: #32668

- Add
[tool_call_timeout_millis](https://github.com/cline/cline/pull/1904)
field to ContextServerCommand, like in Cline
- Update ModelContextServerBinary to include timeout configuration
- Modify Client to store and use configurable request timeout
- Replace hardcoded REQUEST_TIMEOUT with self.request_timeout
- Rename REQUEST_TIMEOUT to DEFAULT_REQUEST_TIMEOUT for clarity
- Maintain backward compatibility with 60-second default

Release Notes:

- context_server: Add support for configurable timeout for MCP tool
calls

---------

Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>

crates/agent2/src/tests/mod.rs

@@ -2477,6 +2477,7 @@ fn setup_context_server(
                     path: "somebinary".into(),
                     args: Vec::new(),
                     env: None,
+                    timeout: None,
                 },
             },
         );