Set SourceMap Value based on Webpack Config

[nicholascm]

This PR contains a:

• bugfix
• new feature
• code refactor
• [] test update .... working on this
• typo fix
• metadata update

Motivation / Use-Case

Basically when switching over to use terser-webpack-plugin I wasted some time trying to figure out why sourcemaps weren't working when I had configured it in the plugins for webpack, only to realize I needed to pass sourceMap: true to our TerserPlugin.

I saw that the webpack defaults actually already do this, and it seems to make sense to do it here as well and remove the config.

#71

Breaking Changes

With this change, the default for sourceMap defers to the webpack configuration devtool or plugins that use the SourceMapDevToolPlugin to define sourcemaps instead of defaulting to false.

Additional Info

[jsf-clabot]

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[codecov]

Codecov Report

Merging #95 into master will increase coverage by 0.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #95      +/-   ##
==========================================
+ Coverage   98.23%   98.25%   +0.01%     
==========================================
  Files           5        5              
  Lines         283      286       +3     
  Branches      113      116       +3     
==========================================
+ Hits          278      281       +3     
  Misses          5        5

Impacted Files	Coverage Δ
src/index.js	98.1% <100%> (+0.03%)	⬆️

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[alexander-akait]

Thanks for PR, it is breaking change, so we will merge this for v2.0, anyway thanks for PR

[alexander-akait]

Partial fixed for 2.0.0, it is invalid use

compiler.options.plugins.some(
              (p) => p instanceof SourceMapDevToolPlugin
            ))

because plugin doesn't support some devtool values, we try to fix it in webpack@5 and then fix it here

Anyway thanks for PR