Fix for status always in PENDING_CREATE for Edge service router

Fix for status always in PENDING_CREATE for Edge service router

The root cause is when deployment finished, we only update router status to
active if the status is in pending create. The problem happens when the
background sync thread update router status to active, so the status update
for vcns_router_binding table is skipped. We fixed this by seperating
checking and updating status for router and binding table.

Also fixed an issue where Edge is not deleted if neutron service is
restarted. The root cause is when neutron service restarts, the cache for
router type is empty. And because we delete the router from db before
we delete Edge, we're not able to locate the router from db to determine
the router type. The fix is to use binding table to determine the router
type.

Also piggyback a missing attribute for updating Edge interface. It must have
been removed by accident when resolving conflict during service plugin merge.

Closes-Bug: #1226229
Change-Id: I3d0639d245e71ea2a3faba70fef1a0ebb87e19fd