Improve support for removeparam in standard mode

[fmarier]

Besides being used as privacy-harming tracking vectors (covered by Brave's own filter since 2019), query string parameters are also removed for other reasons in custom rule sets, and are involved in certain kinds of ads.

At the moment, support for removeparam rules in adblock lists is gated on users being in aggressive mode which means that:

• removeparam rules added by users (directly in brave://settings/shields/filters or via a custom list) will be silently ignored unless the user also opts into aggressive mode
• Video ads from SSAI (server-side ad insertion) systems will not be blocked in standard mode

Perhaps we can fix both of these limitations by adding a new metadata field to https://github.com/brave/adblock-resources/blob/master/filter_lists/list_catalog.json and gating removeparam on that instead.

[fmarier]

For the release notes: Add support for removeparam in custom rules when adblocking is set to standard mode.

[stephendonner]

Verified PASSED using

Brave | 1.63.121 Chromium: 121.0.6167.57 (Official Build) nightly (x86_64)
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Revision | 875b8d7b36b12cd0707de7d638e05f9da6238ef5
OS | macOS Version 11.7.10 (Build 20G1427)

Steps:

1. installed 1.63.121
2. launched Brave
3. loaded brave://adblock
4. added ||example.com^$removeparam=test to the Custom Filters section
5. clicked Save
6. loaded https://example.com/?test=true

Confirmed that the ?test=true param was removed

example	example	example

[hffvld]

Verified on Pixel 7 using version(s):

Device/OS: Pixel 7 / panther_beta-user 14 AP11.231215.009 release-keys
Brave build: 1.63.146
Chromium: 121.0.6167.139 (Official Build) beta (64-bit) 

Filed follow-up issue #35845

STEPS:

1. Install and Launch Brave 1.63.146
2. Go to brave://adblock OR Three-dot menu > Settings > Brave Shields & privacy > Content Filtering > Create custom filters
3. Add ||example.com^$removeparam=test to the Custom Filters section > Save
4. Go to https://example.com/?test=true > Verify that ?test=true must be removed from the URL search bar

ACTUAL RESULTS:

• Verify that the URL bar must not contain ?test=true when Block trackers & ads in Standard mode
• Observed that ?test=true is not removed from the URL search bar

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