To be implemented with future optiSLang versions

Server commands `close` and `stop_gently` are not properly working in optiSLang 2023R1 batch mode, therefore they were commented out and are not accessible for the user. It should be fixed and tested in a future optiSLang release.
- [ ] `stop_gently`
- execution finished notifcation not issued on optiSLang server side
- [ ] `close`
- bug on optiSLang server side, it doesn't send response after unregistration of listeners

Following server commands are incomplete, `oSL Python API` was temporarily used, but should be replaced when fixed on oSL server side:
- [x] `connect_nodes` and `disconnect_slot`
- neither works with inner slots

Start by checking how the server commands stop_gently and close are exposed in the Python API and review their behavior with a future optiSLang release. Done means stop_gently issues the execution-finished notification and close receives a response after listener unregistration; verify both commands with tests or batch-mode checks.

Written by the indexing model from the issue text.