Standardize the relation between the popup condition, BarProp.visible, and noopener/noreferrer

[arai-a]

related to #5872

Steps:

1. Open https://arai-a.github.io/window-open-features/test.html
2. select "popup", "noopener", "noreferrer" radio buttons
3. click "open window"

Results:

• Chromium: a minimal popup window is opened, and window.locationbar.visible is true
• Firefox: a minimal popup window is opened, and window.locationbar.visible is false
• Safari: a new window is opened, and window.locationbar.visible is true

The behavior between Chromium and Firefox diverges because the effect of noopener/noreferrer isn't specified in the spec.

The behavior is covered by the following testcase, that expects "is popup" becomes false if noopener or noreferrer is specified.
https://github.com/web-platform-tests/wpt/blob/master/html/browsers/the-window-object/window-open-popup-behavior.html

To reflect the behavior, either of the following needs to be tweaked, to take noopener/noreferrer into account,
depending on whether the hint for popup condition ("is popup") should be true or false for noopener:

(A) Set "is popup" to false if noopener is true

https://html.spec.whatwg.org/multipage/nav-history-apis.html#apis-for-creating-and-navigating-browsing-contexts-by-name:popup-window-is-requested

The window open steps, given a string url, a string target, and a string features, are as follows:
...
12.
  1. Set targetNavigable's active browsing context's is popup to the result of checking if a popup window is requested, given tokenizedFeatures.

https://html.spec.whatwg.org/multipage/nav-history-apis.html#dom-barprop-visible

(B) Store noopener or related value to browsing context and use it in BarProp.visible getter

The visible getter steps are:
...
  3. Return the negation of browsingContext's top-level browsing context's is popup.