Make workflow translations easier to manage

Some translations must be duplicated in the current implementation.

The workflow graph translations are managed server side with i18n .properties file (node name, transition name)
Other properties must be translated with .json files at the UI level: node name, node directive, workflow actions (usually the same as transitions)

This results in duplicated translations for the node name and transition names. It also makes it difficult to translate the first time because it's not clear what is translated where.