bug: imports are duplicated in modules that contain multiple declarations in NgModule-based applications

### Prerequisites

- [X] I agree to follow the [Code of Conduct](https://ionicframework.com/code-of-conduct).
- [X] I have searched for [existing issues](https://github.com/ionic-team/ionic-angular-standalone-codemods) that already report this problem, without success.

### Codemod version

0.0.7

### Current Behavior

When running the codemod against a project which is still NgModule-based, where a module contains multiple declarations, the imports are duplicated where they exist in each of the modules declarations

### Expected Behavior

Imports of the standalone components should be unique within the module

### Steps to Reproduce

1. Have a project that is still NgModule-based and that has a module with multiple declarations using the same ionic components
2. Run the codemod
3. Observe the resulting module has duplicated imports of the standalone ionic components

### Code Reproduction URL

_No response_

### Additional Information

_No response_