[near-operation-file] Allow named import

**Is your feature request related to a problem? Please describe.**

I would like to generate my backend types in a local workspace package and maybe export something else from there.

**Describe the solution you'd like**

A property like `namedExportName: 'Types'` that, when set, would generate code like `import { Types } from '@company/schema-package';` instead of `import * as Types from '@company/schema-package';`