Support arithmetic operations with scalar

[Alexander-Makaryev]

In [1]: import dpctl.tensor as dpt

In [2]: import numpy

In [3]: a = numpy.arange(4)

In [4]: b = dpt.from_numpy(a)

In [5]: b * 2
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-5-e8bdcb44ebff> in <module>
----> 1 b * 2

TypeError: unsupported operand type(s) for *: 'dpctl.tensor._usmarray.usm_ndarray' and 'int'

In [6]: 2 * b
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-6-fde996378900> in <module>
----> 1 2 * b

/localdisk/work/amakarye/miniconda3/envs/dpnptc4_internal/lib/python3.8/site-packages/dpctl/tensor/_usmarray.pyx in dpctl.tensor._usmarray.usm_ndarray.__mul__()

/localdisk/work/amakarye/miniconda3/envs/dpnptc4_internal/lib/python3.8/site-packages/dpctl/tensor/_usmarray.pyx in dpctl.tensor._usmarray._dispatch_binary_elementwise()

AttributeError: 'int' object has no attribute '__array_namespace__'