Add custom filter list URLs

[cuba]

Description:

Add the ability to add custom filter lists similar to desktop found in the following page:

Additional Information

[Uni-verse]

Verified on iPhone X running iOS 16.3.1 using version 1.50 (23.4.25.20)

Custom Filter List UI

• Confirmed custom filter list URLs can be added to the list.
• Confirmed custom filters can be disabled.
• Confirmed custom filters can be deleted by swipe gesture or in edit mode.
• Confirmed duplicate custom filters cannot be added.
• Confirmed error message is shown for non-https urls in the field.
• Confirmed multiple custom urls can be added.
• Confirmed Last updated message when script was last updated is shown in the contents.
• Confirmed Download failed is shown when custom url fails to load.

Example	Example	Example	Example	Example	Example	Example

Shields/Blocking Tests

Test Plan: #6857 (comment)

Using Custom filter URL - https://gist.githubusercontent.com/cuba/f13fce20b8fbd043ac8174e39ba16788/raw/af09db2fbda948dcf7a90781716c51f5e36f2237/TestAdBlockRules.txt

• Ensured that It will remove a script from https://twitch.tv/ and will result in the blocked count to be 1 (testing script blocking)
• Ensured that header is removed in https://example.com/ (testing cosmetic filtering)

twitch.tv	example.com

• Ensured all values return true on test page - https://dev-pages.brave.software/filtering/scriptlets.html
• Ensured all values return true and blocked count is 19 on test page - https://test-pages.privacytests.org/tracking_content.html
• Ensured disabled shields will disable the scripts blocking.

Example	Example	Example	Shields DOWN

Upgraded Profile

• Ensured custom filter list URLs can be added and are applied on websites when upgrading from 1.49.1 -> 1.50.x
• Ensured custom filter list URLs can be added and are applied on websites when upgrading from 1.49.x -> 1.50.x