text: Title: Get all 1st & 3rd party cookies and not only 1st party cookies
  Body: Hello,
  
  I am trying to scan a website and get the list of all cookies being registered on the browser.
  Currently pyppeteer only provide me first party but when going to a specific website I am seeing on the chrome console 3rd party as well.
  
  ```
      def logit(event):
          req = event._request
          #print("{0} - {1}".format(req.url, event._status))
          request_listing.append(req.url)
  
      async def main():
          browser = await launch({"headless": True })
          page = await browser.newPage()
          page._networkManager.on(NetworkManager.Events.Response, logit)
          await page.goto(url, {'waitUntil' : 'networkidle0'})
          cookies = await page.cookies()
          for i in cookies:
              cookies_listing.append(i)
              print(i)
          await browser.close()
  
      asyncio.get_event_loop().run_until_complete(main())
  ```
  
  exemple with comet.co
  
  ```
  {'name': 'amplitude_id_a2f618bc2c6571209b432a6d22e0f5eccomet.co', 'value': 'eyJkZXZpY2VJZCI6ImRjZTU1ZGRhLTkyNTEtNDJiMC1iOGRhLTc3ZGI5OWE2Mjg3MlIiLCJ1c2VySWQiOm51bGwsIm9wdE91dCI6ZmFsc2UsInNlc3Npb25JZCI6MTYwMjMzMzMzNzg2MywibGFzdEV2ZW50VGltZSI6MTYwMjMzMzMzNzg2MywiZXZlbnRJZCI6MCwiaWRlbnRpZnlJZCI6MCwic2VxdWVuY2VOdW1iZXIiOjB9', 'domain': '.comet.co', 'path': '/', 'expires': 1917693337, 'size': 297, 'httpOnly': False, 'secure': False, 'session': False}
  {'name': '_gid', 'value': 'GA1.2.1422141854.1602333338', 'domain': '.comet.co', 'path': '/', 'expires': 1602419737, 'size': 31, 'httpOnly': False, 'secure': False, 'session': False}
  {'name': '_gat_UA-107043263-8', 'value': '1', 'domain': '.comet.co', 'path': '/', 'expires': 1602333397, 'size': 20, 'httpOnly': False, 'secure': False, 'session': False}
  {'name': 'crisp-client%2Fsession%2F051870fd-b2bd-4d74-a0c1-88725018f1c1', 'value': 'session_8fd4f048-586b-4d22-af18-d0301fc8c9a2', 'domain': '.comet.co', 'path': '/', 'expires': 1618101338, 'size': 105, 'httpOnly': False, 'secure': False, 'session': False, 'sameSite': 'Lax'}
  {'name': '_dc_gtm_UA-107043263-1', 'value': '1', 'domain': '.comet.co', 'path': '/', 'expires': 1602333397, 'size': 23, 'httpOnly': False, 'secure': False, 'session': False}
  {'name': 'gtm_currentTrafficSource', 'value': 'utmcsr=(direct)|utmcmd=(none)|utmccn=(not set)', 'domain': '.comet.co', 'path': '/', 'expires': -1, 'size': 70, 'httpOnly': False, 'secure': False, 'session': True}
  {'name': '__cfduid', 'value': 'd84d6d9952a739fac9f148fef2f2ef89b1602333336', 'domain': '.www.comet.co', 'path': '/', 'expires': 1604925336.061463, 'size': 51, 'httpOnly': True, 'secure': False, 'session': False, 'sameSite': 'Lax'}
  {'name': 'gtm_initialTrafficSource', 'value': 'utmcsr=(direct)|utmcmd=(none)|utmccn=(not set)', 'domain': '.comet.co', 'path': '/', 'expires': 1664541337, 'size': 70, 'httpOnly': False, 'secure': False, 'session': False}
  {'name': '__cfruid', 'value': '06216443fbff24b89f6a6b78a2d7e043de2697bf-1602333337', 'domain': '.www.comet.co', 'path': '/', 'expires': -1, 'size': 59, 'httpOnly': True, 'secure': True, 'session': True}
  {'name': '_dc_gtm_UA-107043263-5', 'value': '1', 'domain': '.comet.co', 'path': '/', 'expires': 1602333397, 'size': 23, 'httpOnly': False, 'secure': False, 'session': False}
  {'name': '_ga', 'value': 'GA1.2.211232657.1602333338', 'domain': '.comet.co', 'path': '/', 'expires': 1665405337, 'size': 29, 'httpOnly': False, 'secure': False, 'session': False}
  {'name': '__utmzzses', 'value': '1', 'domain': '.comet.co', 'path': '/', 'expires': -1, 'size': 11, 'httpOnly': False, 'secure': False, 'session': True}
  ```
  
  
  What i see from my chromium application and cookie listing is:
  <img width="762" alt="Capture d’écran 2020-10-10 à 14 38 40" src="https://user-images.githubusercontent.com/5289306/95655278-60ff8580-0b06-11eb-9265-24da48c8689c.png">
  
  
  Is there a way to get all cookies listed or pyppeteer is limited in somehow to the current domain ? 
  
  Thanks for the help !
  
  
  edit: seem in pupeteer the command should be
  `var data = await page._client.send('Network.getAllCookies');
  `
  but i don't see any comparison in the documentation.