Adapt Che-Theia to upstream changes (Webpack)

[azatsarynnyy]

Is your task related to a problem? Please describe.

There are breaking changes made in upstream Theia by the commit eclipse-theia/theia@fa84afa
It breaks Che-Theia build. See the attached logs for the details.

Describe the solution you'd like

Need to adapt Che-Theia to the upstream changes.

Describe alternatives you've considered

Additional context

Che-Theia build output

@eclipse-che/theia-assembly: Failed to resolve module: filenamify
@eclipse-che/theia-assembly: [webpack-cli] Error: Unknown option '--env.cdn=./cdn.json'
@eclipse-che/theia-assembly: [webpack-cli] Run 'webpack --help' to see available commands and options
@eclipse-che/theia-assembly: Error: webpack exited with an unexpected code: 2.\n    at ChildProcess. (/home/theia-dev/theia-source-code/dev-packages/application-manager/lib/application-process.js:67:28)\n    at ChildProcess.emit (events.js:314:20)\n    at maybeClose (internal/child_process.js:1022:16)\n    at Process.ChildProcess._handle.onexit (internal/child_process.js:287:5)
@eclipse-che/theia-assembly: info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
@eclipse-che/theia-assembly: error Command failed with exit code 1.
lerna ERR! execute callback with error
lerna ERR! Error: Command failed: yarn run build
lerna ERR! Failed to resolve module: filenamify
lerna ERR! [webpack-cli] Error: Unknown option '--env.cdn=./cdn.json'
lerna ERR! 
lerna ERR! [webpack-cli] Run 'webpack --help' to see available commands and options
lerna ERR! 
lerna ERR! Error: webpack exited with an unexpected code: 2.
lerna ERR!     at ChildProcess. (/home/theia-dev/theia-source-code/dev-packages/application-manager/lib/application-process.js:67:28)
lerna ERR!     at ChildProcess.emit (events.js:314:20)
lerna ERR!     at maybeClose (internal/child_process.js:1022:16)
lerna ERR!     at Process.ChildProcess._handle.onexit (internal/child_process.js:287:5)
lerna ERR! error Command failed with exit code 1.
lerna ERR! 
lerna ERR! $ theia build --mode production --config cdn/webpack.config.js --env.cdn=./cdn.json --env.monacopkg=@theia/monaco-editor-core@0.20.0 && yarn run override-vs-loader
lerna ERR! info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
lerna ERR! 
lerna ERR!     at /home/theia-dev/theia-source-code/node_modules/execa/index.js:236:11
lerna ERR!     at runMicrotasks ()
Error: Command failed: yarn run build
Failed to resolve module: filenamify
[webpack-cli] Error: Unknown option '--env.cdn=./cdn.json'
[webpack-cli] Run 'webpack --help' to see available commands and options
Error: webpack exited with an unexpected code: 2.
    at ChildProcess. (/home/theia-dev/theia-source-code/dev-packages/application-manager/lib/application-process.js:67:28)
    at ChildProcess.emit (events.js:314:20)
    at maybeClose (internal/child_process.js:1022:16)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:287:5)
error Command failed with exit code 1.
$ theia build --mode production --config cdn/webpack.config.js --env.cdn=./cdn.json --env.monacopkg=@theia/monaco-editor-core@0.20.0 && yarn run override-vs-loader
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
    at /home/theia-dev/theia-source-code/node_modules/execa/index.js:236:11
    at runMicrotasks ()
    at processTicksAndRejections (internal/process/task_queues.js:97:5) {
  code: 1,
  killed: false,
  stdout: '$ theia build --mode production --config cdn/webpack.config.js --env.cdn=./cdn.json --env.monacopkg=@theia/monaco-editor-core@0.20.0 && yarn run override-vs-loader\n' +
    'info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.\n',
  stderr: 'Failed to resolve module: filenamify\n' +
    "[webpack-cli] Error: Unknown option '--env.cdn=./cdn.json'\n" +
    '\n' +
    "[webpack-cli] Run 'webpack --help' to see available commands and options\n" +
    '\n' +
    'Error: webpack exited with an unexpected code: 2.\n' +
    '    at ChildProcess. (/home/theia-dev/theia-source-code/dev-packages/application-manager/lib/application-process.js:67:28)\n' +
    '    at ChildProcess.emit (events.js:314:20)\n' +
    '    at maybeClose (internal/child_process.js:1022:16)\n' +
    '    at Process.ChildProcess._handle.onexit (internal/child_process.js:287:5)\n' +
    'error Command failed with exit code 1.\n',
  failed: true,
  signal: null,
  cmd: 'yarn run build',
  timedOut: false,
  exitCode: 1
}
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
The command '/bin/sh -c if [ -z $GITHUB_TOKEN ]; then unset GITHUB_TOKEN; fi &&     yarn ${YARN_FLAGS}' returned a non-zero code: 1

[azatsarynnyy]

Webpack 4 supports both formats for providing the arguments: --env arg and --env.arg
https://v4.webpack.js.org/api/cli/#environment-options

But Webpack 5 doesn't support the old format --env.arg
https://webpack.js.org/api/cli/#environment-options

Fixed in the PR eclipse-che/che-theia#1105

[azatsarynnyy]

Passing the args to Webpack is fixed. But the welcome page is broken now

<img> tags have src='/' instead of base64 encoded images.
I continue the investigation.

[azatsarynnyy]

detected in the logs:
2021-05-26 14:36:54.892 root ERROR Request getProduct failed with error: mime.getType is not a function Params: TypeError: mime.getType is not a function

[azatsarynnyy]

The fix is proposed in eclipse-che/che-theia#1134