Add 'Private tabs' settings section

[iccub]

Under Tabs section.
It will have two settings: private tabs persistence and biometric unlock

[Uni-verse]

Verified on iPhone X running iOS 16.5.1 using app version 1.57 (23.8.18.16)

Case: Fresh Profile

• Verified Test Plan in Fix #7855: Add 'Private tabs' settings section #7868 (comment).
• Ensured enabling private mode lock will prompts user to authenticate.
• Ensured disabling Require Face ID toggle and enabling Browser lock setting still works.
• Ensured user is able to enter passcode to unlock private tabs when face id fails.
• Ensured user is able to cancel authentication.
• Ensured disabling Keep Private Tabs toggle will close all private tabs.
• Ensured that Private tabs are not cleared if switching tab mode or exiting browser when Keep Private Tabs enabled

Example	Example	Example	Example

Case: Existing Profile

• Verified Test Plan in Fix #7855: Add 'Private tabs' settings section #7868 (comment).
• Ensured enabling private mode lock will prompts user to authenticate on existing profile.
• Ensured user is able to enter passcode to unlock private tabs when face id fails.
• Ensured disabling Require Face ID toggle and enabling Browser lock setting still works.
• Ensured user is able to cancel authentication.
• Ensured disabling Keep Private Tabs toggle will close all private tabs.
• • Ensured that Private tabs are not cleared if switching tab mode or exiting browser when Keep Private Tabs enabled

Case: Private tab entry points

• Ensured opening private tab works from NTP works
• Ensured opening private tab works using + works
• Ensured opening private tab works from promo widget
• Ensured opening private tab works from widgets on lockscreen
• Ensured opening private tabs works from iOS home screen
• Ensured opening articles on news widget in private tab when enabled

Case: Browser Lock enabled

• Ensured disabling Require Face ID toggle and enabling Browser lock setting still works.
• Ensured enabling both Require Face ID and Browser Lock will require authentication for both launching browser and private tabs access.

Case: Private Browsing Mode

• Verified activating Private Browsing will remove the Private Tabs setting menu