Fixes settings content page loading error.

[mkarolin]

This removes "Performance" item from the advanced items on the page. We moved Performance from its own page (and path) to living under the System settings. Because there's no Route.path for this item the page throws an exception. The item doesn't make much sense on the content page since we consider it more of a systemwide setting (with the ability to add individual sites to always keep active, but that's hardly a reason to show it on the content page).

Resolves brave/brave-browser#35479

Submitter Checklist:

• I confirm that no security/privacy review is needed and no other type of reviews are needed, or that I have requested them
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally:
  • npm run test -- brave_browser_tests, npm run test -- brave_unit_tests wiki
  • npm run lint, npm run presubmit wiki, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

[brave-builds]

A Storybook has been deployed to preview UI for the latest push

[kjozwiak]

Verification PASSED on Win 11 x64 using the following build(s):

Brave | 1.64.15 Chromium: 121.0.6167.75 (Official Build) nightly (64-bit)
-- | --
Revision | 3f8c7a58cc920583b5c0dc81eaa6234a7ef8528c
OS | Windows 11 Version 23H2 (Build 22631.3007)

Using the STR/Cases outlined via brave/brave-browser#35479 (comment), ensured that Site and Shield Settings was loading without any issues within brave://settings/privacy as per the following:

Example (Broken)	Example (Fixed)