GraphQL Plugin

### Clear and concise description of the problem

We need a GraphQL plugin to reduce boilerplate code needed to start using rstore with a GraphQL API.

### Suggested solution

```ts
const graphqlPlugin = createGraphqlPlugin({
url: '/graphql',

// Optionally customize requests
onFetch: (payload) => {
return { fieldName: '', params: {}, 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.