New devfile based stacks should contain samples

Description

Currently a Che stack (i.e. java-maven) is associated to one or more samples (e.g. web-java-petclinic and console-java-simple). But often different samples of the same stack requires different settings (env variables, memory, commands) and making generic stacks that work with every project is hard.

Another point is that from a UX point of view it’s more straightforward to select a vue.js or a angular stack rather than selecting the node js stack and then the angular sample.

So this issue is about the proposal to associate every stack to one unique project sample. The project, as well as the commands, would be specified in the the stack devfiles. The user would still be able to override the sample stack project and commands.

[tolusha]

@l0rd @metlos @tsmaeder If nobody minds I will start working on react sample

[sparkoo]

@l0rd yes, I would close this one as well. We have all devfiles we want merged and following issues should be solved separately.