Update to use new plots infrastructure in Slicer

[fedorov]

[fedorov]

cc: @lassoan @che85

[Kmacneil0102]

@lassoan MultiVolumeExplorer has plotting options for "displaying log scale" for both the X and Y axis. Is there a way to replicate this with the new plots API?

[lassoan]

It is supported by VTK charts, just not yet exposed through the MRML interface. I'll add it then.