Java: Add XADD command (Stream commands)

[acarbonetto]

Issue #, if available:

Description of changes:

Add xadd command

Example:

// without options
String streamId = client.xadd("key", Map.of("name", "Sara", "surname", "OConnor").get();
System.out.println("Stream: " + streamId);

// with Options 
// Option to use the existing stream, or return null if the stream doesn't already exist at "key"
StreamAddOptions options = StreamAddOptions.builder().id("sid").makeStream(Boolean.FALSE).build();
String streamId = client.xadd("key", Map.of("name", "Sara", "surname", "OConnor"), options).get();
if (streamId != null) {
    assert streamId.equals("sid");
}

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[Yury-Fridlyand]

Transaction IT is missing

[Yury-Fridlyand]

Please, update IT for type: https://github.com/aws/glide-for-redis/blob/961a1bb91bda110f7ea4865c37809aebfdd5b970/java/integTest/src/test/java/glide/SharedCommandTests.java#L1192-L1193

[Yury-Fridlyand]

1. Fix merge conflicts
2. Transaction IT is missing. With ID option you can define the return value I think.

[Yury-Fridlyand]

@acarbonetto please resolve conlicts