Add a button to clear all the notifications

In some cases, when Norton Download Insight or Auto Protect detect multiple threats, a large number of alerts will appear in the bottom right corner. It is time-consuming to clear all the notifications one by one. So, it will be better to add a button to clear all the notifications when the number of notifications is large (>5). Alternatively, if there are a lot of warnings, Norton may temporarily pause them and ask the user to access all of them in Security History.