moveToDirectory loses the import statements' extension

[shinebayar-g]

Describe the bug

Version: 25.0.1

When moveToDirectory is used, the import statements' extensions are lost.

To Reproduce

import { Project } from "ts-morph";

const project = new Project({
    tsConfigFilePath: path.join(packagePath, 'tsconfig.json'),
    manipulationSettings: {
        indentationText: IndentationText.TwoSpaces,
        quoteKind: QuoteKind.Double,
        insertSpaceAfterOpeningAndBeforeClosingNonemptyBraces: true,
        useTrailingCommas: true,
    },
});

sourceFile.addImportDeclaration({
    moduleSpecifier: '../App.js',
    namedImports: ['App'],
});

sourceFile.moveToDirectory('subDir');

Expected behavior

Without moveToDirectory is used, import statement looks like this.

import { App } from '../App.js';

After

import { App } from '../../App'; // .js extension is lost.

Other move methods like moveImmediately also seems to be affected.

tsconfig

{
  "compilerOptions": {
    "lib": ["ES2022"],
    "target": "ES2022",
    "module": "Node16",
    "moduleResolution": "node16",
    "declaration": true,
    "strict": true,
    "skipLibCheck": true,
    "noFallthroughCasesInSwitch": true,
    "noEmitOnError": true
  }
}

[shinebayar-g]

It became a blocker for users who have "moduleResolution": "nodenext" in their tsconfig.

[kingston]

Yup also encountered this issue. I narrowed it down to these lines where it seems extensions are stripped:

https://github.com/dsherret/ts-morph/blob/a1c61c7e04928de5d8fc12f32a76e3ed5b7ffea1/packages/ts-morph/src/fileSystem/Directory.ts#L876C1-L879C1

I can try to make a PR for this if helpful.