Simplified compute (lower/upper)

[jorgecarleitao]

Replaced compute_lower and compute_upper by compute_utf8, and renamed modules accordingly.

Also removed unused code warnings in compilation without flags.

[codecov]

Codecov Report

Merging #847 (14b16ef) into main (f70116d) will increase coverage by 0.00%.
The diff coverage is 96.87%.

@@           Coverage Diff           @@
##             main     #847   +/-   ##
=======================================
  Coverage   71.44%   71.45%           
=======================================
  Files         335      334    -1     
  Lines       17986    17986           
=======================================
+ Hits        12850    12851    +1     
+ Misses       5136     5135    -1     

Impacted Files	Coverage Δ
src/compute/utils.rs	100.00% <ø> (+4.34%)	⬆️
src/error.rs	46.15% <ø> (ø)
src/compute/regex_match.rs	78.37% <87.50%> (+2.51%)	⬆️
src/compute/utf8.rs	100.00% <100.00%> (ø)
src/compute/arithmetics/time.rs	26.60% <0.00%> (+0.91%)	⬆️

---

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 f70116d...14b16ef. Read the comment docs.