Merge scripts in test/e2e2 and hack/demo-env

[jannfis]

Is your task related to a problem? Please describe.

Many of the scripts in test/e2e2 and hack/demo-env feel (and probably are) redundant, as they do the same things:

• Setup a vcluster environment and install Argo CD in various degrees of completeness
• Start the principal from the current code base
• Start the agent(s) from the current code base

That makes changes to one or the other cumbersome, and both scripts will slowly drift apart.

Describe the solution you'd like

It would be great if we can use one single set of scripts for both scenarios, e2e tests and the demo env.

Describe alternatives you've considered

n/a

Additional context

n/a

[jopit]

I'll take a look at this.