Save version of used extension packages in Measure/Sequence

[MatthieuDartiailh]

Form my point of view the determination of the versions is best handled by the dependency plugin. As the analysis is not necessarily the the same for all objects, this would be best handled by the collectors. The workflow would then be :

• before saving analyse all dependencies (including runtimes as some runtime may include additional extension packages)
• require the dependency to analyse the used extension packages (for task it can be as easy as looking for the base module in which the task is declared, but it may be better to remember it from registration) and return a set of used extension packages
• identify the origin packages of the pre and post hook and also the monitors (not for the sequences obviously)
• write it at the root of the config under a version node