Changed the method to get current project id to use the new context information scheme. Removed (now) unused method getLastOpenedProject() from WorkbenchService.

Issue: GCP-9026
Reviewer: RebeccaB
Moved the method to determine current IBDB user id to a common place before further refactoring and correction for multi-user scenario.

Issue: GCP-9026
Reviewer: RebeccaB