Add support for reading files from disk

[OlivierJM]

Is your feature request related to a problem? Please describe.
As a user, I would like to be able to easily migrate the contents that is available in SparkEd.

Describe the solution you'd like
When a new version of the app is installed or upgraded all files should easily be moved to another server, the system should be able to read files from disk(storage).

Describe alternatives you've considered
N/A

Additional context
This is an alternative to the synchronization that we've been working on, making it possible to copy files and move them between different servers.

[OlivierJM]

I have been thinking about this and we might not need it since we are saving all the files in the GridFS meaning we should be able to port all files via a mongodb dump.
I will be experimenting with this to make sure that it works as expected