Add Default Ep Status to WebAPI CMD_ShowAddNew

This adds an optional argument to set future episode status.

WebAPI CMD_ShowAddNew was not updating "default_ep_status" when adding new shows to function "addShow" in  "show_queue.py".  So new shows were having "default_status_after" set to None.  Leaving new shows added via webapi not being set to "wanted" or anything useful, requiring a manual episode status change to "wanted".