axis: introduce steps_position_precision to motor controllers, and use it to determine delta in _get_motion

Resolve "Wago: module 750-562 wrong reading in unipolar mode"

Closes #1537

See merge request !2269

Resolve "setpoint motor controller to be replaced by soft axis"

Closes #359

See merge request !2278

Nxwriter optimize vds

See merge request !2282

The special feature of ramp generator for hexapiezo can be achieved
by motion hook. If more complicated ramping is needed, the regulation
framework is here to help.

Feature widget for count and positioners

See merge request !2251

Resolve "Crazy management of signs and limits in BLISS"

Closes #1520, #1542, and #1551

See merge request !2252

[ci] ct writer tests xfail

See merge request !2288

[icat] read with timeout

See merge request !2283

[icat] Attributes like proposal, sample and dataset can be temporary unavailable for reading after changing state.

Move tests around for better files organization

Ensure user pos stays the same in case of steps_per_unit update
Swap limits and change sign if steps_per_unit changes sign

axis: make offset and sign writable properties, raise an exception if controller cannot change dial position, improved lprint messages

Return low_limit and high_limit settings values

axis: _set_position_and_offset: offset is 0 if it is very close to 0 (floating point errors), always display message with sign and offset if position is changed