Add support for loading tiger server nodes "on the fly"

[svbergmann]

There exists a step

Gegeben sei TGR lade TigerGlobalConfiguration aus Datei "tiger-env.yaml"

which we would like to use because we have a slightly different test environment setup for each feature file. We tried to use this step to spawn servers, e.g. tiger-zion but somehow, it did not work, although tiger found the config file.
Could you please investigate this issue?

Also, it would be nice if the step

Gegeben sei TGR starte Server {tigerResolvedString} 

would work, to adjust the running servers per feature or scenario. This did not work on our end because the server node names where not found.