Closes #629

[oleksandr-pavlyk]

Implement dpctl.utils.get_execition_queue( queue_list ).

A test is added too.

In [1]: import dpctl, dpctl.utils

In [2]: q1 = dpctl.SyclQueue("gpu")

In [3]: q2 = dpctl.SyclQueue("gpu")

In [4]: q3 = dpctl.SyclQueue("cpu")

In [6]: dpctl.utils.get_execution_queue([q1]) is q1
Out[6]: True

In [7]: dpctl.utils.get_execution_queue([q1, q1, q1]) is q1
Out[7]: True

In [8]: dpctl.utils.get_execution_queue([q1, q2, q1]) is q1
Out[8]: True

In [9]: dpctl.utils.get_execution_queue([q1, q3, q2]) is None
Out[9]: True

[coveralls]

Coverage increased (+0.5%) to 74.511% when pulling bf9e159 on equivalent_queues-629 into 7110541 on master.

[reazulhoque]

In which version of dpctl will this be included?