Feat : can select the maximum size of file i want to syncronize locally

## Expected

One parameter for each tracim instance, where I can put the maximum size of file where sync is active.

## Use case

I not have a very good connexion and I don't want to lost my time to synchronise unnecessary big file.

For exemple, I want to use trsync to syncrhronize office document from space but not picture or something like that from the same space.

So if I put maximum size like 2Mio, I'm sure that it is not taking to much time to download all usable content.