Notification: Sync user conflict

[paulbert]

Similar to #4129, but for notifications. The notifications intended for nation/community user will show up for both users with the same name.

[paulbert]

Note that the notification has to be created in the planet which the team member is not a part of.

For example, if the member is a part of the team on nation but not community, the notification will need to be created on the community (add message, add members to team, etc) because the notifications created on the nation will (correctly) not sync.

[lmmrssa]

@paulbert community will not always be online so not sure how we update it on community from nation

[paulbert]

@lmmrssa This doesn't require changing community from nation. It only requires filtering the list of notifications so ones with a userPlanetCode that does not match the currently logged in planetCode do not show up.