[meta.yaml / Che plug-ins]: Add dependencies section

[benoitf]

Is your task related to a problem? Please describe.

We have some runtime dependencies for plug-ins.
For example VS Code java debug VS Code extension is depending on VS Code java
(we have other examples)

So we should add that information in meta.yaml, so if user is selecting VS Code java debug it would notify that VS Code java will be selected as well.

Also, at runtime, it can check if the configuration is consistent and prevent to start a workspace or remove failed plug-ins.

Describe the solution you'd like

Add dependencies section in meta.yaml, where we can depend on one/several other Che plug-ins.

-dependencies:
  -id: redhat/java/latest

or

-dependencies:
  -reference: https://gist.../yaml

Additional context

From UX, if a che plug-in is selected with dependencies, it should show that new plug-ins will come with it.

if a plug-in is depending on another plug-in and is not defining any container, it will use the dependency container.

But if a container is specified, the dependency plug-in will use this pre-defined container.

example:

• vscode-java defines java11 image container
• vscode-quarkus depends on vscode-java and specify a spec/container image `quarkus``

then, there is a graph quarkus --> java and then, vscode-quarkus.vsix and vscode-java.vsix will use the same container which will be using quarkus image

So, there are graphs, and the root node image should always be used (instead of the leaf container)

If there are multiple graphs, some options:

1. each root node will have its own container
   for example let say
   quarkus --> java and spring-boot --> java , if quarkus is defining quarkus-image and spring-boot is defining springboot-image, two containers will be deployed, one with quarkus-image and with both java and spring vsix. The same with springboot-image with both java and spring vsix

2. another option: there is an error. We can either use quarkus or spring boot plug-ins but not the same.

3. Note that due to merge of containers with the same image, if quarkus is using java11 image and spring-boot is also using java11 image, despite that there are two graphs, as the image definition is the same, both quarkus, java, spring-boot vsix will be added in the same container using java11image

related to #15272

[ibuziuk]

@benoitf I put P2, but feel free to update priority

[l0rd]

I think we discussed that in the case of multiple graphs (2 plugins sharing the same dependency like quarkus and spring-boot both depending on java), in scenario n.2, we would have:

• asked the user to choose in what image to run all the plugins in the graph when there is an interactive session (like user dashboard or chectl)
• returned an error in non interactive sessions (i.e. when using DevWorkspace CustomResource)