Update long range entanglement tutorial (#3493)

This notebook brings substantial updates to the long-range entanglement
tutorial to support the novel capabilities. In particular:

- [ ] removed post-processing technique and text
- [ ] removed randomized certification of fidelity and corresponding
text
- [ ] limit number of qubits measured to amount currently supported (16)
- [ ] use hellinger fidelity of the bell pair created by the CNOT
between the terminal qubits of the chain as measure of performance

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Co-authored-by: abbycross <[email protected]>

Author: miamico