Have consistent behavior of SPUBLISH within multi/exec like regular command

[sundb]

This PR is based on the commits from PR #12944.

Allow SPUBLISH command within multi/exec on replica

Behavior on unstable:

127.0.0.1:6380> CLUSTER NODES
39ce8aa20f1f0d91f1a88d976ee1926dfefcdf1a 127.0.0.1:6380@16380 myself,slave 8b0feb120b68aac489d6a5af9c77dc40d71bc792 0 0 0 connected
8b0feb120b68aac489d6a5af9c77dc40d71bc792 127.0.0.1:6379@16379 master - 0 1705091681202 0 connected 0-16383
127.0.0.1:6380> SPUBLISH hello world
(integer) 0
127.0.0.1:6380> MULTI
OK
127.0.0.1:6380(TX)> SPUBLISH hello world
QUEUED
127.0.0.1:6380(TX)> EXEC
(error) MOVED 866 127.0.0.1:6379

With this change:

127.0.0.1:6380> SPUBLISH hello world
(integer) 0
127.0.0.1:6380> MULTI
OK
127.0.0.1:6380(TX)> SPUBLISH hello world
QUEUED
127.0.0.1:6380(TX)> EXEC
1) (integer) 0

[oranagra]

this also affects the PUBSUB command, including PUBSUB HELP.

right below this line, we have a loop iterating on each command (handling their keys), why can't we move the previous check we had (or better yet use doesCommandHaveChannelsWithFlags) into the loop, and then set a flag named pubsubshard_included to be used in the code below the loop.?

[sundb]

PUBSUB command doesn't enter getNodeByQuery().
pubsub_cmd->flags&CMD_MOVABLE_KEYS == 0 and pubsub_cmd->key_specs_num == 0

    !(!(c->cmd->flags&CMD_MOVABLE_KEYS) && c->cmd->key_specs_num == 0 &&
          c->cmd->proc != execCommand))
    {
        int error_code;
        clusterNode *n = getNodeByQuery(c,c->cmd,c->argv,c->argc,
                                        &c->slot,&error_code);
       ....
    }

[oranagra]

LGTM