feat(dataaccess): add GIW connection factory method

Add CreateGiwConnectionAsync to IDbConnectionFactory and DbConnectionFactory
for connecting to the GIW Oracle database. This connection is needed for the
StatusCode data sync pipeline.

- Reuses existing CreateOracleConnectionAsync helper with "GIW" data source
- Follows same pattern as JDE, JDEStage, and CMS connections
- Includes 4 unit tests covering missing/empty/invalid connection strings

NEW/src/JdeScoping.DataAccess/DbConnectionFactory.cs

@@ -87,6 +87,12 @@ public class DbConnectionFactory : IDbConnectionFactory
         return await CreateOracleConnectionAsync("CMS", ct).ConfigureAwait(false);
     }
 
+    /// <inheritdoc/>
+    public async Task<OracleConnection> CreateGiwConnectionAsync(CancellationToken ct = default)
+    {
+        return await CreateOracleConnectionAsync("GIW", ct).ConfigureAwait(false);
+    }
+
     private async Task<OracleConnection> CreateOracleConnectionAsync(string dataSource, CancellationToken ct)
     {
         var connectionString = _configuration.GetConnectionString(dataSource);