`toImport` doesn't handle comma separated declaration exports

### Describe the bug Reported by @AloisSeckar in https://github.com/nuxt/nuxt/discussions/34010. I'm not sure if something changed, but a file like: ```ts export const FOO = 'foo' export const BAR = 'bar' ``` gets compiled into: ```ts export const FOO='foo',BAR='bar' ``` which **unimport doesn't handle correctly**. ### Additional context _No response_ ### Logs ```sh ```