Dictionary<string, JsonElement> overload for CallToolAsync

[anuchandy]

Currently, if a caller has a Dictionary<string, JsonElement>, they must convert each JsonElement to object to use the CallToolAsync API since it requires Dictionary<string, object?>. But given internally CallToolAsync already special handles JsonElement and underlying SendRequestAsync supports JsonElement, would it make sense to add an overload that accepts Dictionary<string, JsonElement>? This would avoid requiring callers to perform to-object conversion or rely on implementation details by casting.

We encountered this in Azure MCP Server, and due to the Dictionary<string, object?> constraint, it requires unnecessary conversions or serialization and deserialization operations within hot path