Add setting to hide "Mark all as read"

[albin-engstrom]

I've used this great extension for many years and have twice, although not recently, accidentally clicked "Mark all as read" which is quite a hassle when one is dealing with many unread emails for one reason or another. Especially when spread out over time with many read ones in-between.

It's close to "Mark as read" which I click often, so just a slight slip of the hand when clicking can, and has, lead to undesirable results.

It would be lovely to simply have a setting to hide the "Mark all as read" button to eliminate the risk and worry, I personally never use it