Remove unused Bundle properties

[DS-INRAE]

The following properties are present in Bundle.properties for some translations but are not used in the Dataverse code :

• account.emailvalidation.header

• account.emailvalidation.token.exists

• Check for more unused properties to have a more exhaustive list

• Remove unused properties for translations that had them (split into all translations)

[qqmyers]

It may be that these existed in the Dataverse version that the translation was for. E.g. the French translation looks like it was for 5.10 so it probably has extra and missing values w.r.t. Dataverse 6.2.