Add additional common parameters

[doddatpivotal]

I'd like to see the following additional options:

iterate-cluster-context: this would be placed in tiltfile for allow_k8s_context vlaue
namespace: this would replace the default namespace in the tiltfile
code-git-repo: replaces sample git repo in the workload.yaml file

[trisberg]

@paulcwarren @lisamburns can someone from your team can take a look at this suggestion?

[paulcwarren]

I am not sure I understand what is being suggested here. Are you suggesting additional variables in the templates?