Avoid session blocking

[markus-moser]

Sessions should be write closed when no write operations are needed anymore to avoid session blocking.

This topic is not urgent at all but has the potential to dramatically improve the perfomance within studio UI.

Please let's have some discussion about it.

[github-actions]

Thanks a lot for reporting the issue. We did not consider the issue as "Pimcore:Priority", "Pimcore:ToDo" or "Pimcore:Backlog", so we're not going to work on that anytime soon. Please create a pull request to fix the issue if this is a bug report. We'll then review it as quickly as possible. If you're interested in contributing a feature, please contact us first here before creating a pull request. We'll then decide whether we'd accept it or not. Thanks for your understanding.