Add trigger/gate multiplexor mode support

[reszelaz]

This PR assumes Sardana implements trigger/gate multiplexor mode.

Added:

• multiplexor configuration using active_input axis parameter

Removed:

• DefaultMotor controller property
• unused SetAxisPar() and GetAxisPar() methods

Changed:

• Expect dial position in SynchOne()
• Adapt to new API of StartOne() and PreStartOne()

I think that this controller does not remove the synchronization configuration after the measurement process and IMO it should be done. Imagine moving the motor in parallel to the, but not part of the, measurement process. But I would treat it out to the scope of this PR.

[rhomspuron]

We should implement the auto_esync on the synchone