Fix pi_check not handling large numbers properly

[enavarro51]

Summary

Fix #4777

Details and comments

This PR fixes a problem where large numbers were being displayed as pi/0. Now any number not a multiple of pi and larger than the largest fraction that pi_check will handle will be returned as is.

from qiskit.circuit import QuantumCircuit, Gate

def my_gate(*args):
    return Gate('my_gate', num_qubits=1, params=list(args))
    
qc = QuantumCircuit(1)
qc.append(my_gate(1e9), [0])
qc.draw()

     ┌────────────────┐
q_0: ┤ my_gate(1e+09) ├
     └────────────────┘

[1ucian0]

Thanks a lot!