`typed-ipc`: Return cleanup functions when subscribing via main thread `IpcListener`

[psychedelicious]

Clear and concise description of the problem

I want an easy way to unsubscribe individual listeners and handlers to have more granular control over IPC events.

As of 06b577a, cleanup functions are returned from the renderer process's IpcListener subscription methods. It would be nice for the main process's IpcListener to do the same.

Suggested solution

I'll submit a PR with a simple implementation.

Alternative

Manage subscriptions manually.

Additional context

No response

Validations

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