DWaveCliqueSampler should have solver property at top level

[JoelPasvolsky]

Description DWaveCliqueSampler is not a composite with a child solver so I'd expect it to have a .solver.name property at top level analogous to DWaveSampler.:

>>> sampler_clique.solver.name
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-7-2f60abd45f90> in <module>
----> 1 sampler_clique.solver.name

AttributeError: 'DWaveCliqueSampler' object has no attribute 'solver'

To Reproduce See above.

Expected behavior I think .solver.name should be copied to the top level.

Environment:

• OS: Win
• Python version: 3.7

Additional context You can do this:

>>> sampler_clique.child.solver.name
Out[8]: 'DW_2000Q_6'

[arcondello]

That is an implementation detail of DWaveSampler, not at all guaranteed by the API. If we want to expose the solver name, I think we should implement a more general way.