[declarativeNetRequest] Ability to redirect web link navigations to a new tab/window

[tophf]

This is useful for extensions that handle a certain MIME type via Content-Type response header (a userscript/userstyle manager, PDF, media viewer) and show their UI for the resource in a new tab or window, particularly in a simple popup window without distractions like tabs, address bar, toolbars or menus.

With webRequestBlocking it's easy: we cancel the navigation in the original tab and open a new tab/window passing the URL along.

Possible solutions for MV3 (all must require a host permission because a URL is exposed):

1. Add chrome.webRequest.onBlockedDeclaratively event with ruleIds: [1,2,3] property added to the standard webRequest filter parameter.
2. Add "blockAndNotify" or "blockAndNotifyWebRequest" to the action's type string.
3. Add notifyWebRequest boolean to the rule dictionary, but it's weird because it only makes sense when blocking.
4. Add openIn or retarget or newTarget property in the "redirect" dictionary with values like "tab", "window" however it will also require chrome.declarativeNetRequest.setWindowOptions(opts) so extensions can set the position and size of the window like {type: 'popup', left: 123, top: 100, width: 500, height: 300} to avoid having a non-customizable fugly huge popup like the one opened by chrome.identity API.