Fix/subscriptionmgr indexerror

[a-kleinf]

Make the timeout configureable to wait for the SDC Consumers event sink to be started. This avoids invalid subscription requests. Raises RuntimeError if event sink was not started in specified time.

Handle invalid subscription requests on SDC Provider side - sends soap faults specified in WS-Eventing.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have updated the changelog accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.