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.

Start by tracing the transports that call McpSchema.deserializeJsonRpcMessage(jsonMapper, string) and inspect how MCPJsonMapper is supplied. Determine how transports can accept Java input types and schemas, then verify that request inputs deserialize to Java objects and complex outputs serialize without an additional Map-based conversion.