Deprecate hasModuleSideEffects in favor of moduleSideEffects and ensure it is mutable on ModuleInfo

[lukastaegert]

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

This fixes an inconsistency in the naming i.e. we are using the moduleSideEffects option in the resolveId, load and transform hooks, but on ModuleInfo it is called hasModuleSideEffects. This becomes more problematic if you want to change this property explicitly on ModuleInfo.

This PR does several things:

• Add a new property moduleSideEffects on ModuleInfo (e.g. via this.getModuleInfo()) that takes the role of hasModuleSideEffects
• Add a deprecation warning when explicitly accessing hasModuleSideEffects and strictDeprecations is true
• Make hasModuleSideEffects non-enumerable to avoid accidentally triggering the warning and basically hide the old option (though it still works to prevent breaking changes)
• Ensure that moduleSideEffects can be written during build time, which is important if you write e.g. an entry point proxy plugin that needs to set this flag to true for the original entry point (I also updated the inject-polyfill example in the docs to reflects this)

[github-actions]

Thank you for your contribution! ❤️

You can try out this pull request locally by installing Rollup via

npm install rollup/rollup#mutable-module-side-effects

or load it into the REPL:
https://rollupjs.org/repl/?pr=4379

[codecov]

Codecov Report

Merging #4379 (62abf0e) into master (d57cfa0) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #4379   +/-   ##
=======================================
  Coverage   98.72%   98.72%           
=======================================
  Files         205      205           
  Lines        7311     7318    +7     
  Branches     2083     2083           
=======================================
+ Hits         7218     7225    +7     
  Misses         34       34           
  Partials       59       59           

Impacted Files	Coverage Δ
src/Chunk.ts	100.00% <ø> (ø)
src/utils/traverseStaticDependencies.ts	100.00% <ø> (ø)
src/ExternalModule.ts	100.00% <100.00%> (ø)
src/Graph.ts	100.00% <100.00%> (ø)
src/Module.ts	100.00% <100.00%> (ø)
src/ModuleLoader.ts	100.00% <100.00%> (ø)

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