Determine if the geupgradeassetroot is necessary if no changes are made to the data format

[tst-ccamp]

As a follow-up to #373, determine if running geupgradeassetroot is strictly necessary if the data format is not changed. One benefit to this would be allowing users to do downgrades. If we determine that it is not necessary, write follow-up ticket(s) to update code to work with older versions of the data without performing the upgrade.

[tst-lsavoie]

There is a file at /gevol/assets/.config/.fusionversion that contains the current version number. We'll need to update the handling for this file if we decide to go forward with this.