Feat improve java interop

[abnegate]

What does this PR do?

Add coroutine continuation wrapper for easier use from Java

Before:

        account.get(new Continuation<io.appwrite.models.Account>() {
            @NonNull
            @Override
            public CoroutineContext getContext() {
                return EmptyCoroutineContext.INSTANCE;
            }

            @Override
            public void resumeWith(@NonNull Object o) {
                if (o instanceof Result.Failure) {
                    Result.Failure failure = (Result.Failure) o;
                    failure.exception.printStackTrace();
                    return;
                }
                
                System.out.println((io.appwrite.models.Account) o);
            }
        });

After:

        account.get(new CoroutineCallback<>((account, error) -> {
            if (error != null) {
                error.printStackTrace();
                return;
            }

            System.out.println(account)
        }));

Test Plan

Manual test

Related PRs and Issues

Supercedes #575

Have you read the Contributing Guidelines on issues?

Yes

[stnguyen90]

I didn't test any of this and I know barely anything about Continuations, but the syntax looks great! It's really clean!

I'm only concerned about how much it will bother people with there being such a breaking change 😕

[abnegate]

I'm only concerned about how much it will bother people with there being such a breaking change 😕

@stnguyen90 It's not breaking 😉 CoroutineCallback extends Continuation so you can pass either