There's a few aspects to your question:
1) to gracefully "pause" SolarWinds, you can use the Service Management utility (Start, SolarWinds Orion, Advanced Features, Solarwinds Service Manager) - choosing "shutdown everything". Once the updates are done (assuming you haven't had a reboot, which automatically starts the poller services) you use "Start everything".
But it seems like your point is more about not re-triggering alerts, than it is about just stopping and starting SolarWinds.
At one end of the spectrum, you would need to have a separate event correlation engine that took in events from SolarWinds, and sent them to the alerting engine (or ticket system). The event engine would ensure that it didn't trigger the same alert for the same device, if there was already a ticket open in the first place. But not everyone has that. In fact, almost NOBODY has that.
A second option would be to set up a custom property - "SWMaint". Then select a significant node - maybe your database server or even the polling engine if you choose to monitor your polling engine WITH your polling engine (don't laugh, there are a couple of good reasons to do it!).
NOW... you have to update all of your alerts with a suppression rule
I'll wait for you to pick yourself up off the floor, because I am famous for saying NEVER to use the suppression tab. But in this case, it will actually do what you want.
Every alert you create has to have the suppression tab set so that:
Node = <my important node>
SWMaint = Yes
Finally, set the SWMaint property to "yes" for your important node.
At this point, no alert will fire since the suppression conditions are true.
Do your update, wait for the dust to settle, and then set the SWMaint property to "NO". Alerts will now run as usual.