Reduce boilerplate in quartz app enclave

[dangush]

Summary

We want to minimize the amount of code a quartz app dev needs to write / understand while limiting their ability to customize their application. Currently, the main.rs file of quartz enclave/ has a lot of boilerplate.

Copying comments from @hu55a1n1 :
This is somewhat intentional, as we don't want the user/dev to forget to add the quartz CoreService. But I think there are other ways to achieve that. e.g. ->

trait QuartzServerExt {
    fn quartz_builder(
        config: Config,
        sk: Arc<Mutex<Option<SigningKey>>>,
        attestor: DefaultAttestor,
    ) -> Router;
}

impl QuartzServerExt for Server {
    fn quartz_builder(
        config: Config,
        sk: Arc<Mutex<Option<SigningKey>>>,
        attestor: DefaultAttestor,
    ) -> Router {
        Server::builder().add_service(CoreServer::new(CoreService::new(
            config,
            sk.clone(),
            attestor.clone(),
        )))
    }
}

Users might want the flexibility to specify their own config e.g. light client opts, etc.
Users may also want to add more services.

To do

• Discuss what improvements we'd like to implement

Acceptance Criteria

• todo