cosmetic filtering doesn't handle vetted search engines correctly if they have subdomains

[pes10k]

Currently we do not apply cosmetic filtering to privacy respecting ads on search partners in the default setting (we still hide then in the aggressive mode). However, the check for "is this a vetted search engine" page fails incorrectly for search engine subdomain pages.

For example, currently cosmetic filtering is default off for https://startpage.com/sp/search (this is expected). However, its default on for startpage subdomains (e.g., https://www.startpage.com/sp/search). The same is true for all the expected, vetted domains.

[SergeyZhukovsky]

Created a follow up to cover that functionality with tests #14259

[LaurenWags]

Labelling as QA/Blocked until uplift is completed

[kjozwiak]

Removing QA/Blocked as this was uplifted via brave/brave-core#8014 👍

[LaurenWags]

Verified passed with

Brave	1.21.65 Chromium: 88.0.4324.182 (Official Build) beta (x86_64)
Revision	73ee5087001dcef33047c4ed650471b225dd8caf-refs/branch-heads/4324@{#2202}
OS	macOS Version 10.15.7 (Build 19H512)

Verified test plan from brave/brave-core#8011 (comment) and brave/brave-core#8011 (comment) with different examples.

Example - Under Armour

Standard	Aggressive

Example - Windows

Standard	Aggressive

---

Verification passed on

Brave | 1.21.68 Chromium: 89.0.4389.58 (Official Build) (64-bit)
-- | --
Revision | 1a139f28ecc27719439e37c6b1533cee999cb802-refs/branch-heads/4389@{#1134}
OS | Windows 10 OS Version 2004 (Build 19041.804)

Verified test plan from brave/brave-core#8011 (comment) and brave/brave-core#8011 (comment) with different examples.

Example - iphone X

Standard	Aggressive

Example - samsung tab

Standard	Aggressive

---

Verification passed on

Brave	1.21.68 Chromium: 89.0.4389.58 (Official Build) (64-bit)
Revision	1a139f28ecc27719439e37c6b1533cee999cb802-refs/branch-heads/4389@{#1134}
OS	Ubuntu 18.04 LTS

Verified test plan from brave/brave-core#8011 (comment) and brave/brave-core#8011 (comment) with different examples.

Example - Samsung s21

Standard	Aggressive

Example - apple

Standard	Aggressive

[srirambv]

Verification passed on OnePlus 6T with Android 10 running 1.21.68 x64 build

• Verified first part ads are listed when search for specific terms
• Verified clicking on the ad loads a new tab that loads google.com result and then redirects to the first party page

---

Verification passed on Samsung Tab A with Android 10 running 1.21.68 x64 build

• Verified first part ads are listed when search for specific terms
• Verified clicking on the ad loads a new tab that loads google.com result and then redirects to the first party page

OnePlus 6T	Samsung Tab A