Add  create and delete to Jumpgate volume API

    1. Support SL portable storage create operation via jumpdate
    2. Support SL portable storage delete operation via jumpdate
    3. Add unittest coverage for jumpgate volume create/delete

Change-Id: I9cd6acb0832279fdfa5080e728ecaef9ac9de638
Okay. :( It just gives me a sad that polling is needed like this.