Export from data explorer

[kgodey]

This is a meta issue tracking the implementation of this project.

Outcome

Currently, Mathesar's UI only supports exporting data from tables, which limits utility. Users should also be able to export data from explorations.

For our MVP, we'd like to keep this as simple as possible.

Related

• Multiple requests from users for this via user feedback form.
• Prior product work (private document) Exporting Tables & Explorations
• Support exporting tables #2268

[zackkrida]

For @Anish9901 and anyone else who plans to work on this, I'd like to point out some thoughts left by @pavish in a related issue: #4388 (comment)