jqueue: Add common RPC error handling function
jqueue: Add common RPC error handling function

We didn't decide yet what exactly it should do with failed nodes.

Reviewed-by: ultrotter


mbakke/ganeti,apyrgio/snf-ganeti,grnet/snf-ganeti,ganeti/ganeti,grnet/snf-ganeti,ganeti/ganeti,dimara/ganeti,leshchevds/ganeti,leshchevds/ganeti,bitemyapp/ganeti,leshchevds/ganeti,ganeti/ganeti,yiannist/ganeti,andir/ganeti,onponomarev/ganeti,ganeti-github-testing/ganeti-test-1,andir/ganeti,yiannist/ganeti,mbakke/ganeti,onponomarev/ganeti,bitemyapp/ganeti,ganeti-github-testing/ganeti-test-1,andir/ganeti,apyrgio/ganeti,mbakke/ganeti,apyrgio/snf-ganeti,dimara/ganeti,apyrgio/ganeti,yiannist/ganeti