TimePeriod: properly validate ranges field

[yhabteab]

Just came across this weird behavior. Even though the class compiler generated a proper validator for the ranges field, no one cared to actually call it from within the overridden method, resulting in some weird errors bing displayed instead.

Before

[2025-11-14 16:51:28 +0100] critical/config: Error: Operator + cannot be applied to values of type 'String' and 'Array'
[2025-11-14 16:51:28 +0100] critical/config: 1 error
[2025-11-14 16:51:28 +0100] critical/cli: Config validation failed. Re-run with 'icinga2 daemon -C' after fixing the config.

After

[2025-11-14 16:37:57 +0100] critical/config: Error: Validation failed for object '24x7' of type 'TimePeriod'; Attribute 'ranges' -> 'monday': Invalid type.
Location: in icinga2.conf: 253:5-255:5
icinga2.conf(251):     import "legacy-timeperiod"
icinga2.conf(252):
icinga2.conf(253):     ranges = {
                       ^^^^^^^^^^
icinga2.conf(254):         "monday" = []
                   ^^^^^^^^^^^^^^^^^^^^^
icinga2.conf(255):     }
                   ^^^^^
icinga2.conf(256): }
icinga2.conf(257):
[2025-11-14 16:37:57 +0100] critical/config: 1 error
[2025-11-14 16:37:57 +0100] critical/cli: Config validation failed. Re-run with 'icinga2 daemon -C' after fixing the config.

[jschmidt-icinga]

Makes sense.