Document the known issues related to cookie blocking by different browsers

[azatsarynnyy]

Is your task related to a problem? Please describe

Upstream VS Code has a known issue with the correct WebView work depending on the browser's settings related to the Third-Party Cookies blocking. ATM, it is not documented on the VS Code docs.

The Che user may face such an issue very easily when opening Che in Firefox on Mac OS.
The problem appears as an empty WebView-based page in VS Code UI. Also, the user gets a notification saying:

Describe the solution you'd like

We should document this upstream problem as a known issue and describe the possible options for how the user can work it around by changing the browser's settings.
The details I've described in #21852 (comment).

Describe alternatives you've considered

As a more general solution, we could create a dedicated page in Che docs describing:

• the supported browsers;
• the known issues which are browser-specific;
• particular browser's settings need to be changed in order to ensure stable work;
• collect other browser-specific notes.

Additional context

• Failure to register a ServiceWorker from vscode-cdn.net when opening a Jupyter notebook using VS Code #21852
• Firefox rolls out Total Cookie Protection by default to all users worldwide
• How to turn off Enhanced Tracking Protection in Firefox

[max-cx]

@azatsarynnyy, if possible, please ask the assignee to reach out to the docs team, ideally before opening a PR to the docs repo, so that we can figure out together where to incorporate this new content in the docs. Here's the docs issue: https://issues.redhat.com/browse/RHDEVDOCS-4803.

[azatsarynnyy]

@max-cx I wrote some notes here https://gist.github.com/azatsarynnyy/bb2947b2fef01b2776162713add33505
It can be used as a base for a new docs chapter, probably.

@RomanNikitenko can you please help me to verify how the suggested workaround works on macOS? It would be great if you could check which of the described option works for you.

[RomanNikitenko]

Allow all cookies helped me for the Chrome Incognito mode.

[RomanNikitenko]

About Firefox

I can not reproduce the problem - it works fine for me without any workarounds.
I mentioned it here

Today I tested it for:

• object-detection-rest.git,
  see Failure to register a ServiceWorker from vscode-cdn.net when opening a Jupyter notebook using VS Code #21852
  and
• dockerfile-hello-world,
  see Error "operation is insecure" raised when trying to preview a markdown file in VS Code #21782 (comment)

My settings you can see here:

[azatsarynnyy]

Thanks, @RomanNikitenko for verifying it.
So, there's nothing specific for Mac users anymore.
I've updated https://gist.github.com/azatsarynnyy/bb2947b2fef01b2776162713add33505

[azatsarynnyy]

@azatsarynnyy, if possible, please ask the assignee to reach out to the docs team, ideally before opening a PR to the docs repo, so that we can figure out together where to incorporate this new content in the docs. Here's the docs issue: https://issues.redhat.com/browse/RHDEVDOCS-4803.

@max-cx I've drafted content related to this issue. Please, find it here https://gist.github.com/azatsarynnyy/bb2947b2fef01b2776162713add33505
Do you have an idea what would be the best place for new content?

[azatsarynnyy]

The PR eclipse-che/che-docs#2568 is under review.

[azatsarynnyy]

https://www.eclipse.org/che/docs/next/end-user-guide/troubleshooting-webview-loading-error/