support "XINFO CONSUMERS"

[kkkbird]

add function "XInfoConsumers" as "XInfoGroups", tested on redis 6.0.10

btw: refer to xinfo document, these codes may not workable in future redis release

Note that you should not rely on the fields exact position, nor on the number of fields, new fields may be added in the future. So a well behaving client should fetch the whole list, and report it to the user, for example, as a dictionary data structure. Low level clients such as C clients where the items will likely be reported back in a linear array should document that the order is undefined.

[vmihailenco]

@kkkbird thanks for the contribution - code looks good. Is it possible to add a test?

[kkkbird]

test is added

[vmihailenco]

@kkkbird thank you 👍