feat: make db parallel

[Chronostasys]

No description provided.

[codecov]

Codecov Report

Merging #164 (82ce647) into master (e4174ce) will increase coverage by 0.02%.
The diff coverage is 91.55%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #164      +/-   ##
==========================================
+ Coverage   88.46%   88.49%   +0.02%     
==========================================
  Files          68       68              
  Lines       11604    11745     +141     
==========================================
+ Hits        10266    10394     +128     
- Misses       1338     1351      +13     

Impacted Files	Coverage Δ
src/ast/accumulators.rs	100.00% <ø> (ø)
src/ast/builder/mod.rs	100.00% <ø> (ø)
src/ast/node/pkg.rs	60.89% <0.00%> (-0.35%)	⬇️
src/ast/node/string_literal.rs	0.00% <0.00%> (ø)
src/db.rs	47.82% <46.15%> (-2.18%)	⬇️
src/ast/node/program.rs	88.26% <73.33%> (-0.72%)	⬇️
src/ast/builder/no_op_builder.rs	76.14% <75.00%> (ø)
src/ast/node/operator.rs	80.21% <83.33%> (ø)
src/ast/node/function.rs	90.80% <85.71%> (-0.03%)	⬇️
src/ast/builder/llvmbuilder.rs	90.45% <90.90%> (ø)
... and 11 more