Support i18n in ValidationError

[rymsha]

it should be possible to provide i18n key for ValidationError.

[rymsha]

most of work is done it #9056

Need to agree on i18n keys

system.cms.validation.optionsetOccurrences=OptionSet [{0}] requires min {1} max {2} items selected: {3}
system.cms.validation.minOccurrences=[{0}] requires minimum {1,choice,1#1 occurrence|1<{1} occurrences}: {2}
system.cms.validation.maxOccurrences=[{0}] allows maximum {1,choice,1#1 occurrence|1<{1} occurrences}: {2}
system.cms.validation.site=Data validation error in site config for {0}
system.cms.validation.displayNameRequired=displayName is required
system.cms.validation.nameRequired=name is required