Switch supermuc to autonomous tunnel mode.
Make autonomous tunnel setup more resilient.

This functionality is required on systems like Archer, where multiple agents
potentially run on the same node and an available port needs to be found.

In the process, also remove the dynamic proxy for now.
On "problematic" systems we can use a pre-populated virtenv.
Merge branch 'devel' of github.com:radical-cybertools/radical.pilot into devel