Migrate all browser-level settings from CWS MV2 extensions to Brave-hosted MV2 extensions

[ShivanKaul]

Description

For the 4 MV2 extensions we support in brave://settings/extensions/v2, we auto-migrate the CWS version to the Brave-hosted version. We migrate all the extension settings, but we should also migrate the browser-level extension settings.

These ones specifically:

Steps to reproduce

1. Download uBO from Chrome Web Store
2. In brave://extensions (direct link: brave://extensions/?id=cjpalhdlnbpafiamejdnhcphjbkeiagm), for uBO, set Site access to be "on specific sites" and add https://brave.com.
3. You can also change the other browser-level settings on this page.
4. Now, trigger the auto-migration to the Brave-hosted version of uBO. The steps for this are captured in a different QA issue, ask @boocmp
5. See Site access setting

Actual result

The Site access is reset on the Brave-hosted version, back to all sites.

Expected result

The settings should carry over to the Brave-hosted version of MV2 extension.

Reproduces how often

Easily reproduced

Brave version (brave://version info)

1.94.79 Chromium: 151.0.7922.34 (Official Build) nightly (arm64)

Channel information

• release (stable)
• beta
• nightly

Reproducibility

• with Brave Shields disabled
• with Brave Rewards disabled
• in the latest version of Chrome

Miscellaneous information

No response