BOR UI - business search SI column change

The business search 'significant individual' column includes misleading text for businesses where SIs are not applicable or have not filed significant individuals or where individuals are all redacted from the search.

It also includes firm owners which makes the title of the column incorrect so we either need to remove the firm owners from that column or change the column header (if we do this it should be consistent with what we call the 'person search table' for public users as it also searches over firm owners and SIs)

Design: https://www.figma.com/design/JLmhc9QFKtAXijXsyTCSR8/Search?node-id=726-4084&t=PrruDVRdxwRaCNAB-0

Start in the BOR UI business search entry point and review the current significant individual column, then compare its wording and scope with the public person search table. Use the linked Figma design to resolve the intended header and messages; done means the column no longer misleads users about non-applicable, unfiled, redacted, or firm-owner records.

Written by the indexing model from the issue text.