* start webpack 5 migration

* fixes

* compiles now

* upgrade karma webpack

* drop webpack 4 code branches

* regenerate test output

* Stop testing TypeScript 3.6 and 3.7

* remove flaky test

* delete ignored tests

* upgrade chrome laungcher

* upgrade to 4.1.5

* implement @alexandar-akait's suggestion

* use webpack.sources.RawSource as suggested by @JonWallsten

* upgrade webpack introduce flaky test mechanism for platform

* execution tests on windows execute in c:\source\ts-loader

* ignore test failures on windows

* Update create-and-execute-test.js

* Update create-and-execute-test.js

* Update create-and-execute-test.js

* Update create-and-execute-test.js

* Update create-and-execute-test.js

* Update create-and-execute-test.js

* Update create-and-execute-test.js

* Update create-and-execute-test.js

* Update create-and-execute-test.js

* Update create-and-execute-test.js

* fix test cases on windows (#1273)

* Update after-compile.ts

* Update create-and-execute-test.js

* Update CHANGELOG.md

* make node 12 the minimum version

* Update push.yml

* Update README.md

* remove 3.6 test output

* remove 3.7 test output

* remove 3.8 test output

* remove 3.9 test output

* remove 4.0 test output

* tidy

* fix

* lint should compile too

* delete unused

* remove unused

* upgrade karma

* upgrade fs-extra

* upgrade types and eslint

* remove html-webpack-plugin as unused

* update changelog

* update vanilla example

* use webpack type

* enrich WebpackLoaderContext type

* target es2018

Co-authored-by: Tobias Koppers <tobias.koppers@googlemail.com>