PZP reconnectivity and enrollment fixes

Checks PZH every 20 seconds even if connected. If PZH is not available does socket.destroy to facilitate service discovery to only work on device.
If 2 PZP with same name enroll, PZH assigns a new id to the PZP. PZP then regenerates csr and get it signed by the PZH.

Jira Issue: WP-909
Merge pull request #566 from habibvirji/WP-909-living-labs

PZP reconnectivity and enrollment fixes