Allow scheduler configuration with variable libraries

Variable Libraries would become even more powerful if they could control the activation state of individual schedules instead of only a single scheduler. A pipeline can already have multiple schedules. We use: DEV schedule (06:00) TEST schedule (05:30) PROD schedule (05:00) During deployment, only the appropriate schedule should be enabled for the target environment. This avoids manual changes after deployment and eliminates the need to parameterize schedule times. This would fit naturally with Variable Libraries and Deployment Pipelines.