There are two changes in this commit:
1. Add -X option to redis-cli.
Currently `-x` can only be used to provide the last argument,
so you can do `redis-cli dump keyname > key.dump`,
and then do `redis-cli -x restore keyname 0 < key.dump`.
But what if you want to add the replace argument (which comes last?).
oran suggested adding such usage:
`redis-cli -X <tag> restore keyname <tag> replace < key.dump`
i.e. you're able to provide a string in the arguments that's gonna be
substituted with the content from stdin.
Note that the tag name should not conflict with others non-replaced args.
And the -x and -X options are conflicting.
Some usages:
```
[root]# echo mypasswd | src/redis-cli -X passwd_tag mset username myname password passwd_tag OK
[root]# echo username > username.txt
[root]# head -c -1 username.txt | src/redis-cli -X name_tag mget name_tag password
1) "myname"
2) "mypasswd\n"
```
2. Handle the combination of both `-x` and `--cluster` or `-X` and `--cluster`
Extend the broadcast option to receive the last arg or <tag> arg from the stdin.
Now we can use `redis-cli -x --cluster call <host>:<port> cmd`,
or `redis-cli -X <tag> --cluster call <host>:<port> cmd <tag>`.
(support part of #9899)
4836ae32c7