lxd/operations: Fixes operationsGetByType to filter operations by type correctly
lxd/operations: Fixes operationsGetByType to filter operations by type correctly

 - Filter remote operations by type using GetOperationsOfType.
 - Do not load the serverCert for every remote member.
 - Add a comment about notify=true.
 - Logs a warning if any remote members that had operations of the desired type are skipped because they are offline.

Signed-off-by: Thomas Parrott <6b778ce645fb0e3dde76d79eccad490955b1ae74@canonical.com>

atxwebs/lxd,atxwebs/lxd,stgraber/lxd,atxwebs/lxd,lxc/lxd,hallyn/lxd,lxc/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd,lxc/lxd,hallyn/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,atxwebs/lxd,lxc/lxd,lxc/lxd,hallyn/lxd,stgraber/lxd