[Feature] Implement constructor function for alternating layer ansatz

[ducthanh1991]

Proposition of resolution of #532: Implementation of a constructors function that create a Alternating Layer Ansatz circuit.

Done:

• Implemented the digital strategy to create an ALT circuit

Example of an alt circuit generated with the function for n_qubits=10,m_qubits_block=4,depth=2

To do:

• implement the sdaqc strategy
• implementation of the bdaqc strategy
• implementation of the analog strategy

[awennersteen]

Thanks a lot!

We might take a couple of days to review properly due to slightly busy period, and some holidays being taken on top of that

[chMoussa]

Nice! LGTM, thanks @ducthanh1991