Stream: Handle streamID-related edge cases

This commit solves several edge cases that are related to
exhausting the streamID limits: We should correctly calculate
the succeeding streamID instead of blindly incrementing 'seq'
This affects both XREAD and XADD.

Other (unrelated) changes:
Reply with a better error message when trying to add an entry
to a stream that has exhausted last_id

src/blocked.c

@@ -388,7 +388,7 @@ void serveClientsBlockedOnStreamKey(robj *o, readyList *rl) {
 
             if (streamCompareID(&s->last_id, gt) > 0) {
                 streamID start = *gt;
-                start.seq++; /* Can't overflow, it's an uint64_t */
+                streamIncrID(&start);
 
                 /* Lookup the consumer for the group, if any. */
                 streamConsumer *consumer = NULL;