C2D: Check algorithm images

[alexcos20]

Whenever a compute job is started, it needs a image.
But, there are a couple of constrains:

• is that image available?
• is the right architecture?

So, we need to check this before actually starting the job

Tasks:

• each compute environment should also expose architecture (it must be an array, cause complex engines like k8 can have multiple values)
• during initializeCompute/startCompute/FreeComputeStartCommand we need to:
  • check if image exists
  • get the architecture and check if our compute env is supporting that

PS: I already added docker-registry-client as a dependency, so use that

[jamiehewitt15]

Yeah, this is much needed so that we can also give helpful error messages if the compute job fails. We can display these on the UI side including the vs-code extension and anything else.