[2.4.0] Checkmk Werk 16640 adapted: Ruleset API: Improve custom validation

Werk 16640 was adapted. The following is the new Werk, a diff is shown at the end of the message. [//]: # (werk v2) # Ruleset API: Improve custom validation key | value ---------- | --- date | 2024-03-14T14:49:51+00:00 version | 2.4.0b1 class | fix edition | cre component | checks level | 1 compatible | no To better support the combination of different validation functions, FormSpecs now expect a sequence of validation functions instead of just one for `custom_validate`. The validation of empty inputs is now handled in the new validator `LengthInRange` instead of `DisallowEmpty`. If you used ``` custom_validate=DisallowEmpty() ``` before, use ``` custom_validate=LengthInRange(min_value=1) ``` now. For consistency, `InRange` is renamed to `NumberInRange` ------------------------------------<diff>------------------------------------------- [//]: # (werk v2) # Ruleset API: Improve custom validation key | value ---------- | --- date | 2024-03-14T14:49:51+00:00 version | 2.4.0b1 class | fix edition | cre component | checks level | 1 compatible | no To better support the combination of different validation functions, FormSpecs now expect a sequence of validation functions instead of just one for `custom_validate`. + The validation of empty inputs is now handled in the new validator `LengthInRange` instead of `DisallowEmpty`. + If you used + ``` + custom_validate=DisallowEmpty() + ``` + before, use + ``` + custom_validate=LengthInRange(min_value=1) + ``` + now. For consistency, `InRange` is renamed to `NumberInRange`