Support parameter deserialisation to Java Objects using the MCPJsonMapper

Expected Behavior
Although all the transports provided with the SDK require a jsonMapper they only deserialize inputs as Java maps.
It should be possible to specifiy the Java input types along with the schema so that the transports can deserialize into real Java objects

Same applies for output serialisation. Complex Java types cannot be used directly as output.

Current Behavior

Currently transports use the static method McpSchema.deserializeJsonRpcMessage(jsonMapper, <string>); that cannot be extended and does jsonMapper.readValue(jsonText, MAP_TYPE_REF);

Context

This would greatly simplify applying each request to real java methods with matching parameters. Without that an additional jackson deserialisation is necessary, making the first deserialisation to Map redundant. It's unnecessary code that each implementor must produce.

まず、McpSchema.deserializeJsonRpcMessage(jsonMapper, string) を呼び出すトランスポートを追跡し、MCPJsonMapper がどのように提供されているかを調べます。トランスポートが Java の入力型とスキーマを受け入れる方法を特定し、リクエスト入力が Java オブジェクトにデシリアライズされ、複雑な出力が追加の Map ベースの変換なしでシリアライズされることを確認します。