Server-side batching (SSB)

[bevzzz]

This PR adds BatchContext which implements Server-Side Batching protocol.

List<WeaviateObject<Map<String, Object>>> objects = List.of(...);
List<ObjectReference> references = List.of();
List<CompletableFuture<?>> submitted = new ArrayList<>();
try (BatchContext batch = client.batch.start()) {
  
  // Optional: Define a retry policy that retries each task up to three times.
  Consumer<TaskHandle> retryMax3Times = task -> task.result()
    .thenCompose(result -> result.error().ifPresent(err -> {
      if (task.timesRetried == 3) {
          throw new RuntimeException(err);
      }
      retryMax3Times.accept(batch.retry(task));
    });

  // Submit all objects to the batch
  objects.map(batch::add).map(retryMax3Times).forEach(submitted::add);
  
  // Submit all references to the batch
  references.map(batch::add).map(retryMax3Times).forEach(submitted::add;
}

// Await until all tasks complete
CompletableFuture.allOf(submitted).get();

Description

TODO

[orca-security-eu]

Orca Security Scan Summary

Status	Check	Issues by priority
Passed	Infrastructure as Code	0   0   0   0	View in Orca
Passed	SAST	0   0   0   0	View in Orca
Passed	Secrets	0   0   0   0	View in Orca
Passed	Vulnerabilities	0   0   0   0	View in Orca