Withdrawing a pending invitation

Use 'cancel_invitation' to withdraw a connection invitation that hasn't been accepted yet. The tool returns structured feedback so you know exactly what happened:

- 'withdrawn: true' means the invitation was successfully cancelled and your invitation tracker is updated. - 'already_accepted' means the person already accepted, so it can't be withdrawn. - 'already_withdrawn' means you (or your agent) already cancelled this one. - 'not_found' means there's no pending invitation to cancel.

This is useful for cleaning up invitations sent by mistake, or for agents that need to undo actions automatically.