Allow regular expressions in table column filter

This would enable a couple of frequent use cases:

- Restrict search results to those where the field *only* contains the search term, e.g. `^query$`.
- Match records based on multiple alternative search terms, e.g. `Aachen|Tilburg`.
- Match records based on the presence of multiple words that might not be adjacent, e.g. `comptoir.*almanach`.

Tabulator has a [built-in](https://www.tabulator.info/docs/6.x/filter/#func) `regex` filter function (bottom of the list), so we should be able to just use that.

Start at the table column filter configuration and compare it with Tabulator's built-in regex filter function. Verify filtering for anchored terms such as ^query$, alternatives such as Aachen|Tilburg, and separated words such as comptoir.*almanach; done means these patterns work through the column filter.

Written by the indexing model from the issue text.