BC-9926 - Refactor websocket openCallback to handle closed connection

[bischofmax]

Description

Links to Tickets or other pull requests

Screenshots of UI changes

Approval for review

• DEV: If the API or client code was changed, all necessary code generation or synchronization steps were completed and tested.
• QA: In addition to review, the code has been manually tested (if manual testing is possible)
• All points were discussed with the ticket creator, support-team or product owner. The code upholds all quality guidelines from the PR-template.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud