Feature request: Rename sync device

[alexangas]

Currently it is not possible to rename the name of a sync device. This is problematic if the name you created on mobile needs to be changed. It is worse if you use desktop with more than one Brave install, and couldn't set a name in the first place, as you will have a duplicate.

This request is similar to https://github.com/brave/browser-laptop/issues/9355.