Transforms SelectPauliRot (phase gradient)

[KetpuntoG]

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Context:

A new state of the art decomposition has been added to SelectPauliRot (as a transform) in qml.labs

Possible Drawbacks:

This is a transform so it will not be part of the decomposition graph

[github-actions]

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Please edit doc/releases/changelog-dev.md with:

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.37%. Comparing base (eac7974) to head (58612ba).
⚠️ Report is 302 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #8738   +/-   ##
=======================================
  Coverage   99.37%   99.37%           
=======================================
  Files         589      589           
  Lines       63179    63181    +2     
=======================================
+ Hits        62784    62786    +2     
  Misses        395      395           

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[Qottmann]

On a first pass it looks very nice and clean! Great job @KetpuntoG !
Missing some things in the doc string though

[dwierichs]

Nice work @KetpuntoG, this is so cool to have implemented essentially in a couple of lines 😍

[dwierichs]

Looks good to me, nice work @KetpuntoG 🎉
Can I ask you to add some explanation for the updated ceiling+flooring logic for the rounding? I'm not sure what exactly is going on :D
Approving conditional on that small request :)

[Qottmann]

looks good, thanks @KetpuntoG !

just a small suggestion to update the image