Legal API: prevent actions based on FF (risk)

[severinbeauvais]

The agreed-upon initial implementation of the story is a UI-only solution. This exposes the risk that some external API users could submit some filings for non-BEN businesses.

This ticket is for "optional" work for the Legal API to protect itself. It is proposed that this be done in the Legal Name branch to avoid complex merge issues. It needs to be weighed whether to implement this ticket, depending on:

• when this implementation, in Legal Name branch, could be deployed to Prod
• probability and severity of risk mentioned above
• amount of time of risk exposure (ie, go-live is coming up)
• amount of effort to implement this temporary work (won't be needed after go-live)

cc: @OlgaPotiagalova @vysakh-menon-aot @Mihai-QuickSilverDev

[NaveenHebbale]

EPIC closed- #20066, One ticket kept in Sync Enhancement