T3370
Looking into this more. Really we don't have any need to use the port object to maintain long lived connections. Cashtab extension requests are one-off msg passing. Chrome has method to support this, so use it instead.
Note: The port passing is preserved for address sharing as, in testing, it was nontrivial to remove this extension-side. Also, have not seen the port disconnect error for the address passing feature, so lower priority to patch.