Add a function testing policy health of a node
Add a function testing policy health of a node

Add a function that tests whether a node is in a healthy state
policy wise.  The type is chosen to reflect that of a no-op
operation on a node.

Signed-off-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>
Reviewed-by: Petr Pudlak <9d19625f8ee825a2c398462ed335cbcf98f79c32@google.com>

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