listidentifier postprocessor should consider translations when matching values

Currently for Static Lists (but also DBList) translations are not included in the reverse mapping of list properties.

Thus, the only values that will be taken into account when reverse-looking a static list item are the values associated to the key in the class definition. In standard XWiki, the translations of the values of a static list are overriding the values in the class definition, if any (for example when displaying the options of a list property in edit mode or in view mode). The objective of this issue is to make sure that if the value displayed on the screen by the standard view is used in a source file for the batch import, that value will be correctly reverse-mapped to the key of the property, regardless of where the value comes from (translation or class definition).