Refresh open state system analysis during fetchTree

[bhufmann]

It would be good to work on refreshing the open state system analysis available when opening the view (fetchTree). Right now only state systems are shown that had been opened before the state system explorer is opened the first time. Note, whenever a view is opened a new state system might opened or create. Opening the state system explorer should include those.

Originally posted by @bhufmann in #325 (review)

[theibhir]

Alright I will look into it.