Reuse existing table cell rendering logic, so render_cell() hook works

[simonw]

This plugin currently implements its own custom version of a table display:

https://github.com/simonw/datasette-search-all/blob/5b5f1926d7634ae3ed39f7eaf3fa74325e5d842b/datasette_search_all/templates/search_all.html#L128-L129

This means things like the render_cell() plugin hook are not respected.