UI - Implement Business Lookup for MHR Registration/Transfer/Exemption/Unit Notes submitting party

For Staff Flows - In MHR Registration, Transfer, Unit Notes and Exemption the current submitting party component does not use the business look up. This ticket is to update the submitting party component in MHR Registration and MHR Transfer (all), Exemption and Unit Notes to use the business lookup.

Note: business lookup was previously implemented for adding business owners, however, that included restrictions on which entity types could be selected (e.g. FM was greyed out). For submitting party the business look up should retrieve all Active BC Businesses and all should be valid for selection.

- if no businesses are retrieved the dropdown should state "No Active B.C. businesses found." see design comp

### See Visual Design Comps:

1.1 Submitting Party Business Look Up
https://www.figma.com/file/7iEKHDFXJZGGhp9OOqF3Mi/MHR%2BPPR---Misc-Updates?type=design&node-id=208-104&mode=design

Start by locating the submitting party component and the existing business lookup used for adding business owners. Compare its behavior with the linked Figma design, then verify the lookup across MHR Registration, all MHR Transfer flows, Exemption, and Unit Notes, including the specified empty-results message and selection of all active B.C. businesses.

Written by the indexing model from the issue text.