update LQ generator vector insert order

[josephleekl]

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Context:
Currently in GateImplementationsLM.hpp some generator functions performs two std::vector insertions to the same vector, both to the beginning of the destination vectors.

Description of the Change:
The order is swapped, and the second vector is inserted to the end of the vector. This should be more performant.

Benefits:

Possible Drawbacks:

Related GitHub Issues:

[sc-78933]

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.58%. Comparing base (db137bf) to head (c2f7dcd).
Report is 47 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1009   +/-   ##
=======================================
  Coverage   91.58%   91.58%           
=======================================
  Files         176      176           
  Lines       24535    24535           
=======================================
  Hits        22471    22471           
  Misses       2064     2064           

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[AmintorDusko]

Good job finding and fixing this performance regression.

[LuisAlfredoNu]

LGTM! Thank you @josephleekl

[multiphaseCFD]

Thanks @josephleekl for getting this work done in this PR.