`Cmdable` does not include `StreamCmdable`

[chirino]

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Expected Behavior

Cmdable should have the XAdd() method.

Current Behavior

Cmdable no longer has the XAdd() method.

Possible Solution

Add StreamCmdable to the Cmdable interface.

[lucky-wolf]

Just this.

Our software is now incompatible with 9.2.0

It was fine in 9.0 & 9.1 -- but in 9.2 someone removed StreamCmdable.

Perhaps when someone refactored, they failed to add StreamCmdable to Cmdable interface - breaking all streaming commands?

If it was intentional to remove it - then updating the readme as to how folks are intended to access streamable commands would be appreciated.

Otherwise, restoring this interface as part of Cmdable seems like the right thing to do.

[sethrylan]

Resolved with #2725 and released in v9.2.1