Remove DataFile model

[mathemancer]

Problem

We currently use a DataFile model to help handle uploading data for import into Mathesar. However,

• The model isn't used after the import succeeds
• It's overly complicated
• It's risky to keep users data on the service beyond its usefulness

Proposed solution

We should revamp the import process so that the DataFile model isn't needed, and then remove it.

[aniketkulkarni17]

Hi,
I would like to take up this issue, can you please assign it to me? Also, do we need to remove the DataFile model completely, or replace it with something else?

[mathemancer]

As the issue says, we need to make it so that the import process works without a DataFile model. This implies replacing it with some functionality to upload a file from a user, and then import it into the DB satisfying the current UI without the model.

Re: assigning issues. We don't assign issues to new contributors. If you'd like to work on this you can, you should raise a PR with a solution, and we'll assign the issue to you while we review (if the solution looks viable).