Name Request - Verify business state and business type when validating the incorporation number

**Is your feature request related to a problem? Please describe the problem & source of request.**
A call is being made to CPRD for a variety of request types, but no validation is taking place.

**Describe the solution you'd like - Expected Behaviour**
When a client completes certain request types, they must enter their corp_num (a.k.a. incorporation number or registration number)
We should use this number to look them up in CPRD and verify the following:
- corp_state must be active
- business type must match type in NR being requested

**Describe alternatives you've considered**
You can remove the integration altogether, but then clients may request an NR for the wrong type, or for a historical company.

Start by locating the existing CPRD integration and the request-type handling described in the issue. Trace how corp_num is currently used; done means relevant requests reject inactive corporations and business-type mismatches, with both validations covered.

Written by the indexing model from the issue text.