Feature request: conditional formatting

It's more of a spreadsheet feature than something normally seen in a database GUI client, but I'd love to have the ability to conditionally highlight/format cells based on simple criteria (>, <, ==, not null, etc)

## What software versions are you using?

Postico version:
1.5.8 (4819)

The issue names no files, tests, or entry points. Start by locating the table-cell display path in Postico and define how conditional formatting should apply; done means cells can be highlighted or formatted using the listed criteria, including >, <, ==, and not null.

Written by the indexing model from the issue text.