Improve Monaco upgrade process

[RomanNikitenko]

The issue is based on discussion with @akosyakov @azatsarynnyy @RomanNikitenko
The last upgrade Monaco PR: #7149

The main steps at upgrade Monaco version are the following:

• upgrade monaco-languageclient
• types' signatures alignment
• editor configurations alignment
• testing/fixing

What we could improve:

• upgrade monaco-languageclient
  We have an issue to remove the dependency monaco-languageclient, please see the discussion here: remove dependency to monaco-languageclient #7100

• types' signatures alignment
  This step is very time consuming one, so it would be nice to avoid working on it manually. Anton's (@akosyakov) idea is getting types from the corresponding version of VS Code automatically, for example, by generating index.d.ts file/files. We need more investigation regarding this step.
  Related issue: simplify checking monaco typings #7261

• editor configurations alignment
  At last upgrade @RomanNikitenko did this kind of work in semi-automatic way:
  - read properties from editorOptionsRegistry of VS Code
  - write the data as Json to a file
  - copy to the codeEditorPreferenceProperties of Theia
  - check manually
  The idea for improvement from Anton: read these properties in @theia/monaco module of Theia and fill codeEditorPreferenceProperties.

• testing/fixing
  At last upgrade Monaco version Anton provided integration tests: add integration tests for typescript language #7265. It helped to test the changes and will speed up the process of testing of next Monaco upgrade.
  We consider adding more tests to reduce manual testing, avoid regressions and provide more smooth process of upgrade.

[RomanNikitenko]

@akosyakov @azatsarynnyy
Please feel free to edit the description, add comments and so on if I missed something
thanks!

[azatsarynnyy]

@RomanNikitenko thank you for outlining the possible directions for improving Monaco upgrade process.

ATM working on these improvements is not in our short-term plans however, these are undoubtedly important directions that have to be considered before the next Monaco upgrade.
cc: @akosyakov ^^

[vince-fugnitto]

@colin-grant-work would you agree that the upgrade process for monaco is now improved following the latest update?
For example we no longer rely on monaco-languageclient, the editor-preferences are now automated and for future upgrades things should be far simpler.

[colin-grant-work]

@vince-fugnitto I think the process is definitely better than it was before or than it was when this issue was opened. I'll assign this to myself, and I'll make a PR updating our documentation in the repo and - apart from the PR - in the wiki and close this that way. Keep up the pressure on me to actually do the documentation part :-).

[colin-grant-work]

Closing as done via #11331 where the steps for performing a Monaco upgrade are outlined.