web_extension_mode
Description:
This configures web_view
to treat the content as a WebExtension.
Note that this refers to the web standard WebExtensions and not WebKitWebExtensions.
In practice this limits the Content-Security-Policies that are allowed to be set. Some details can be found in [Chrome's documentation
](https://developer.chrome.com/docs/extensions/mv3/intro/mv3-migration/content
-security-policy).