Mcp Added Status To Dynamic Metadata

Added status information to dynamic metadata and filter state for the MCP filter. This provides visibility into request processing results, such as whether a request was rejected due to body size limits, parsing errors, or duplicate keys. The status message is kept in lower case, as is prefixed by the mcp_, to indicate the filter name. Added checks in integration tests to verify the new status (and other mcp related fields) are logged correctly.