URL pattern Exceptions to tab discarding

This policy makes it so that any URL matching one or more of the patterns it specifies (using the URLBlocklist filter format) will never be discarded by the browser.
This applies to memory pressure and high efficiency mode discarding.
A discarded page is unloaded and its resources fully reclaimed. The tab its associated with remains in the tabstrip, but making it visible will trigger a full reload.

Example value:

example.com
https://*
*