Use `secrets-patterns-db` regexes

[dwisiswant0]

Context: https://github.com/mazen160/secrets-patterns-db

Things to note:

1. Only take patterns with a "high" confidence level.
2. Merge patterns named "Pattern X - N" into a single array, "Pattern X".
3. Slugified pattern name (strip special chars, lowercase'd, "_" as space replacement).