[feat] use superjson for KV API serialization

[HuakunShen]

Describe the problem

https://docs.kunkun.sh/developer/api/kv/
Currently KB only supports standard JSON.parse and JSON.stringify.
Data types like Uint8Array and Date are not supported.

Describe the solution you'd like

Simply replace it with superjson.
See https://www.npmjs.com/package/superjson for the supported data types.

Alternatives considered

No response

Additional context

No response

Contributes

• I am willing to submit a PR to implement this feature

Searched

• I have searched for similar issues and found none