JS: allow the NumberOfEntities keyword for Pack to accept an expression
JS: allow the NumberOfEntities keyword for Pack to accept an expression

Signed-off-by: Harry King <4297d713059dfdc9fd310cd85bf547ea21a2d624@ausenco.com>
Signed-off-by: Harvey Harrison <eadbd6b462bf3c97df0300a934c12bc2e5d1fe51@ausenco.com>

jaamsim/jaamsim,jaamsim/jaamsim,jaamsim/jaamsim,jaamsim/jaamsim