Make variables for current try counter and maximum number of tries available for If Instruction

Current Situation

• JS-2158 makes the $js7MaxTries and $js7TryCount variables available to jobs.
• Use of the variables in an If Instruction within a Retry Instruction will raise the error:

  Error (status=failed, msg=Not in a try or catch block
  

Desired Behavior

• The $js7MaxTries and $js7TryCount variables should be usable in If Instructions within a Retry Instruction.