Feature: Max-relative entropy for quantum states

[vprusso]

Implement a function that calculates the max-relative entropy for quantum states.

The functionality for this should be created in state_props/max_relative_entropy.py with corresponding unit tests found in tests/test_state_props/test_max_relative_entropy.py. Be sure to also update the docs in /docs/states.rst under "Properties of Quantum States" with toqito.state_props.max_relative_entropy.py.

For a definition of max-relative entropy for quantum states, consult:
https://arxiv.org/abs/1905.11629

See related tasks:
Min-relative entropy (quantum states): #40

[vprusso]

Closing as part of task clean-up.