add `type` for type-only imports in generated code

[jeremymeng]

Today generated code is not doing that. example

https://github.com/Azure/azure-sdk-for-js/pull/38649/changes#diff-723be3e2e3e85b1a4e5a1d7b35ff03f1c5d0ae81ca9b2884d76549fa737e96d8

if we have enough information we should generate

import {
  type PagedAsyncIterableIterator,
  buildPagedAsyncIterator,
} from "../../static-helpers/pagingHelpers.js";

it may be easier to implement than splitting the imports into two: type-only and non-type-only