Support for variadic arguments on SCRIPTRUN

[filipecosta90]

Further reference:
https://oss.redislabs.com/redisai/master/commands/#aiscriptrun

Example on how provide an arbitrary number of inputs after the $ sign::

redis> AI.TENSORSET mytensor1 FLOAT 1 VALUES 40
OK
redis> AI.TENSORSET mytensor2 FLOAT 1 VALUES 1
OK
redis> AI.TENSORSET mytensor3 FLOAT 1 VALUES 1
OK
redis> AI.SCRIPTRUN myscript addn INPUTS mytensor1 $ mytensor2 mytensor3 OUTPUTS result
OK
redis> AI.TENSORGET result VALUES
1) FLOAT
2) 1) (integer) 1
3) 1) "42"