Move minimum_holdoff from UHFQC to UHFQA_core (including unit test)

[chellings]

This feature from #651 belongs into the UHFQA_core driver (lower-layer driver shared by TUD and ETH) that was introduced in #656. The feature ended up in the wrong place because the two pull requests were processed in parallel. This pull request moves the minimum_holdoff calculation to the correct class, and also adds the corresponding unit test originally written as part of #651 to the test module of the core driver.

@MiguelSMoreira

[codecov[bot]]

Codecov Report

Merging #681 (5ea6f81) into develop (3072b00) will increase coverage by 0.03%. The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop     #681      +/-   ##
===========================================
+ Coverage    36.18%   36.21%   +0.03%     
===========================================
  Files          302      302              
  Lines        65699    65716      +17     
===========================================
+ Hits         23773    23800      +27     
+ Misses       41926    41916      -10     

Impacted Files	Coverage Δ
...truments/ZurichInstruments/UHFQuantumController.py	35.99% <ø> (+0.03%)	:arrow_up:
...ysical_instruments/ZurichInstruments/UHFQA_core.py	82.27% <100.00%> (+0.34%)	:arrow_up:
...nt_drivers/physical_instruments/test_UHFQA_core.py	100.00% <100.00%> (ø)
pycqed/analysis/analysis_toolbox.py	42.96% <0.00%> (+0.38%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 3072b00...5ea6f81. Read the comment docs.

[MiguelSMoreira]

I have deleted the branch, after having merged it into develop, to cleanup things. If it is still needed, please feel free to restore it!

[chellings]

Thanks for reviewing & merging so rapidly @MiguelSMoreira. Yes, deleting the branch was fine.