LUT maper updates

[aletempiac]

This PR updates the LUT mapper:

• Adding delay relaxation ratio: used for area-oriented mapping by mapping for delay first and then relaxing the required time

[codecov-commenter]

Codecov Report

Merging #582 (fb7e944) into master (8f920b7) will decrease coverage by 0.00%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #582      +/-   ##
==========================================
- Coverage   83.04%   83.03%   -0.01%     
==========================================
  Files         164      164              
  Lines       21176    21178       +2     
==========================================
  Hits        17586    17586              
- Misses       3590     3592       +2     

Impacted Files	Coverage Δ
include/mockturtle/algorithms/lut_mapper.hpp	83.92% <100.00%> (+0.19%)	:arrow_up:
...nclude/mockturtle/algorithms/dsd_decomposition.hpp	87.32% <0.00%> (-4.23%)	:arrow_down:

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