Relations with array of references

### Clear and concise description of the problem

Items can contain references to relations:

```ts
const projectItem = {
title: 'my-project',
tagIds: ['a', 'b', 'c'],
}
```

### Suggested solution

Handle list of values for relation fields.

### Alternative

_No response_

### Additional context

_No response_

### Validations

- [x] Follow our [Code of Conduct](https://github.com/Akryum/rstore/blob/main/CODE_OF_CONDUCT.md)
- [x] Read the [Contributing Guidelines](https://github.com/Akryum/rstore/blob/main/CONTRIBUTING.md).
- [x] Read the [docs](https://rstore.starpad.dev/guide/).
- [x] Check that there isn't [already an issue](https://github.com/Akryum/rstore/issues) that requests the same feature to avoid creating a duplicate.