extensions: repeated use of a namespace for different steps leads to incomplete installation

[jsuchome]

When fuseml is creating a namespace while installing an extension, it labels it so to mark itself as the creator of such namespace. Later, if such labeled namespace is detected, it will not reinstall the content of said namespace (unless explicitly requested).

Now, ideal case if there's one namespace for an extension and it is not needed for extension steps. But we might such situation:

extension E
extension namespace: not defined
install steps:

• step 1:
  helm chart
  namespace: X
• step 2:
  script that needs to check some stuff before applying next step
  namespace: not defined (therefor we cannot have global namespace for the whole extension)
• step 3:
  manifest file
  namespace X

In such case, the actions in step 3 would be skipped because fuseml already created such namespace and would think next attempt to use it means reinstallation. The installation would be incomplete.