feat: new esModule option

[alexander-akait]

This PR contains a:

• bugfix
• new feature
• code refactor
• test update
• typo fix
• metadata update

Motivation / Use-Case

fixes #424 fixes #433

Breaking Changes

No

Additional Info

No

[codecov]

Codecov Report

Merging #475 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master    #475      +/-   ##
=========================================
+ Coverage   88.67%   88.7%   +0.02%     
=========================================
  Files           5       5              
  Lines         424     425       +1     
  Branches       93      94       +1     
=========================================
+ Hits          376     377       +1     
  Misses         46      46              
  Partials        2       2

Impacted Files	Coverage Δ
src/loader.js	89.24% <100%> (+0.11%)	⬆️

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[Cryrivers]

should the semantic equivalence to module.exports = {...} be export const XXX = YYY one-by-one instead of export default {...}, and it might be also better for tree-shaking?