store all object from the project in a specific class object

[Edouard-Legoupil]

A project is managing multiple files:

• data - one of multiple frame
• cleaning log
• weight
• form
• indicators

Now this is managed through a series of frame / stored as csv

We could use the same approach then sdcMicro by creating a specifc class object with all those elements stored in a structured way...
https://github.com/sdcTools/sdcMicro/blob/master/R/0classes.r