Remove build time warning and improve logs

[Kronprinz03]

1. In build time, following warning will be logged when process start does not have any businessKey annotation defined:

[WARNING]  RiskService.Risks: @bpm.process.businessKey not found for process start. Length check will be skipped.

=> Some processes simply do not have a businessKey, therefore either remove this check completely or set it to info level at best.

2. When starting a process, following message will be logged, no matter if the process was actually started or not:

[process] - Starting process eu10-canary.bpm-flying-saucer.riskmanagementbeta.approveNewRisk

=> Check whether it is possible to log another message indicating whether the start was successful or not.