Simplify options for auto-clearing cookies and site data

[Brave-Matt]

Description

At this time, due to both Brave's independent implementations and what is inherited by Chromium, there are too many places in which cookies/site data can set to "be cleared". It makes the process cumbersome and confusing. Users can set the following options to do the same thing (as far as I know):

• Clear data on exit menu (checking the Cookies and site data box)
• Clear cookies and site data when you close all windows
• Forget me when I close this site located in Shields settings

Users should have at most two places to do this — one to clear cookies/site data globally and one to do so on a per site basis. The simplest way to do this would be to remove/hide the Clear cookies and site data when you close all windows option from all platforms.

This way, users can clear cookies/site data globally by checking the aforementioned box in the On exit dialog (Settings --> History --> Clear browsing data —> [On exit]). If they only want to clear data on a specific site (automatically), they can do so by ensuring the Forget me when I close this site option is checked in Shields while they're on the relevant site.

Related

This issue of automatically clearing data is directly related to a previously opened issue that I think warrants more consideration: #10493

cc @rebron @pes10k