fs: extract path conversion and validation to getValidatedPath

Almost all path validations within our file system are combined with:
```js
path = toPathIfFileURL(path);
validatePath(path);
```

So simply extracted them out into `getValidatedPath` function to
`internal/fs/utils.js` to DRY up the code and reduce duplicating them.

PR-URL: #27656
Reviewed-By: Ruben Bridgewater <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Anto Aravinth <[email protected]>
Reviewed-By: Rich Trott <[email protected]>