Multi-root as a default project layout in Che-Theia for simpler multi projects workspaces

[azatsarynnyy]

The goal of this epic is to gather and track the work towards setting the multi-root workspaces as a default project layout in Che-Theia.

Additional context

https://www.eclipse.org/lists/che-dev/msg04068.html

Sub-tasks

Che 7.27

• Multi-root mode is optional, can be enabled with a feature toggle in a Devfile. Multi-root Che Theia Workspaces #17212

Che 7.28

• Multi-root is a default mode when the DevWorkspace engine is used. multi-root workspaces should be default when using Dev Workspaces / devfile v2 #19191

Che 7.29

• Multi-root is a default mode for all workspaces. It can be disabled with the feature toggle in a Devfile. Enable Che-Theia multi-root mode by default for all workspaces #19389
• Adapt the HappyPath tests to the multi-root mode. Adapt the HappyPath tests to Che-Theia multi-root mode #19390
• Enable the multi-root mode for the Devfiles in the Che Devfile Registry Explicitly enable/disable multi-root in devfiles of che-devfile-registry  #19375
• Check single-to-multi root mode migration in Che-Theia Check single-to-multi root mode migration in Che-Theia #19445
• Explorer is empty after switching to che-theia:next Explorer is empty after switching to che-theia:next #19551

Che 7.31

• Enable the multi-root mode for Go devfile Enable the multi-root mode for Go devfile #19476

Che 7.33

• Add /projects as default project when opening the IDE without any projects in the devfile Enhancement: When a workspace has no projects show welcome buttons in the file explorer #19645

[RomanNikitenko]

There are issues related to the multi-root mode:

• Export launch configurations from devfile to workspace config file #18866
• Multi-root: workspace folders auto detection #19101
• allow to customize/provide different projects to be added in workspace root. Could be useful for a maven project to see only sub-folders/modules

If some of them look pretty critical - we could add them to the epic.

[RomanNikitenko]

Another issue was created related to multi-root mode: #19370

[RomanNikitenko]

There is a discussion in comments of the issue #17975 about settings for plugins + multi-root

[azatsarynnyy]

added #19445 as it's important to check before 7.29 release

[azatsarynnyy]

added #19551 to fix in 7.29

[azatsarynnyy]

added #19476 that needs to be fixed before removing the temporary feature toggle

[benoitf]

hello, here is another issue I'm facing with multi-root: #19645

[azatsarynnyy]

hello, here is another issue I'm facing with multi-root: #19645

Thanks! It should be fixed in 7.32, most likely. I've updated the sub-tasks list accordingly.
Also, I've moved #19594 to 7.32 as there's a couple of issues that should be fixed first.

[RomanNikitenko]

I detected one more issue: #19730

[l0rd]

@azatsarynnyy I don't think we need #19594 to be in this epic (i.e. we can close the epic once #19645 is solved)

[azatsarynnyy]

@azatsarynnyy I don't think we need #19594 to be in this epic (i.e. we can close the epic once #19645 is solved)

@l0rd I agree, removed

[azatsarynnyy]

All sub-tasks are done. So, I'm closing the epic.