Preserve displayName and description after WSDL import

[SiebeCorstjens]

Problem

When publishing a SOAP API using a WSDL specification file, APIM's WSDL import process re-derives certain API properties, specifically displayName and description, from the WSDL binding name and overwrites the original values configured for the API (e.g. via apiInformation.json). This causes unexpected metadata drift on every publish run for a SOAP API.

Solution

In putWsdlSpecification (src/common/ApiSpecification.cs), the original displayName
and description are now:

1. Captured from the API's existing DTO (via GetResourceDtoFromApim) before the
   WSDL specification import is performed.
2. Re-applied after the import completes, but only when:
   • The target is the root API revision (ApiRevisionModule.IsRootName), since non-root revisions do not independently own these properties.
   • At least one of the two values (description or displayName) was present beforehand, avoiding unnecessary API calls.