Add support for list of regex in regex.json

**Is your feature request related to a problem? Please describe.**
Many regexes (like phone numbers or coordinates) have several formats. Currently, `|` can be used to separate formats, but it makes regex longer and harder to understand.

**Describe the solution you'd like**
"Regex" should be a list of regexes.

Start by reading regex.json and inspect how its current regex entries are loaded and matched. Define completion as allowing a Regex value to contain multiple regexes while preserving the existing alternative-format behavior; verify the affected matching behavior with the repository's existing tests, if present.

Written by the indexing model from the issue text.