Werk #6425: Improved validation of timeperiods before deletion

When deleting a timeperiod via WATO some validations are made that this time period is not used anymore and can be deleted without issues.

In previous versions this check was checking this places:

• Host & service rules like service / host notification and check periods
• Notification period in user profiles
• Timeperiod exclusions in other timeperiods

These missing validations have been added now:

• Timeperiod condition in notification and alerting rules
• Bulk operation in notification rules
• Timeperiod condition in Event Console rules
• Host & service rules: time specific parameters

CMK-669

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