refactor: improve & simplify types

[sxzz]

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

List any relevant issue numbers:

Description

Improve & simplify types.

[codecov]

Codecov Report

Merging #4675 (df883f0) into master (11d425b) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #4675      +/-   ##
==========================================
- Coverage   99.02%   99.02%   -0.01%     
==========================================
  Files         215      215              
  Lines        7552     7551       -1     
  Branches     2092     2091       -1     
==========================================
- Hits         7478     7477       -1     
  Misses         24       24              
  Partials       50       50              

Impacted Files	Coverage Δ
src/Chunk.ts	100.00% <100.00%> (ø)
src/Graph.ts	100.00% <100.00%> (ø)
src/ModuleLoader.ts	100.00% <100.00%> (ø)
src/utils/options/mergeOptions.ts	100.00% <100.00%> (ø)
src/utils/options/normalizeInputOptions.ts	100.00% <100.00%> (ø)
src/utils/options/normalizeOutputOptions.ts	100.00% <100.00%> (ø)
src/utils/renderChunks.ts	100.00% <100.00%> (ø)

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[lukastaegert]

Really nice changes, thank you! Just one minor comment.

[lukastaegert]

Thanks a lot, great work!

[rollup-bot]

This PR has been released as part of rollup@3.2.2. You can test it via npm install rollup.