[COOP report] Add support for report-only

This adds the support for report-only COOP triggered Browsing context
group switches.
During navigation, besides computing whether COOP triggers a BCG switch,
this also computes if any of the report-only policies would also trigger
a switch if they were effective, the resulting values are stored in
booleans within |CrossOriginOpenerPolicyStatus|.
This booleans are then used to trigger the navigation reports, and in a
follow up to trigger access reports.

Explainer [WIP]:
https://github.com/camillelamy/explainers/blob/master/coop_reporting.md

Specification [WIP]:
whatwg/html#5518

Bug: 1099208
Change-Id: I2cb66ec5cdcd9d5b4658c28f0608bc6b52d0da6b

html/cross-origin-opener-policy/reporting/navigation-reporting/reporting-popup-same-origin-coep-report-to.https.html

@@ -111,7 +111,7 @@
     SAME_ORIGIN,
     "",
     "",
-    `same-origin; report-to="${popupReportEndpoint.name}"`,
+    `same-origin; report-to="${popupReportOnlyEndpoint.name}"`,
     "require-corp",
     [
       {
@@ -127,7 +127,22 @@
           "url": `${location.href}`,
           "type": "coop"
         }
-      },]
+      },
+      {
+        "endpoint": popupReportOnlyEndpoint,
+        "report": {
+          "body": {
+            "disposition": "reporting",
+            "document-uri": /uuid=EXECUTOR_UUID$/,
+            "effective-policy": "same-origin-plus-coep",
+            "navigation-uri": `${location.href}`,
+            "violation-type": "navigation-to-document"
+          },
+          "url": /uuid=EXECUTOR_UUID$/,
+          "type": "coop"
+        }
+      }
+    ]
   ],
   // Open a cross-origin popup with a same-origin COOP report only. A report is
   // sent to both this page's endpoint and the popup's.

html/cross-origin-opener-policy/reporting/navigation-reporting/reporting-popup-same-origin.https.html

@@ -102,7 +102,22 @@
     "",
     `same-origin; report-to="${popupReportOnlyEndpoint.name}"`,
     "",
-    []
+    [
+      {
+        "endpoint": popupReportOnlyEndpoint,
+        "report": {
+          "body": {
+            "disposition": "reporting",
+            "document-uri": /uuid=EXECUTOR_UUID$/,
+            "effective-policy": "same-origin",
+            "navigation-uri": `${location.href}`, // referrer
+            "violation-type": "navigation-to-document"
+          },
+          "url": /uuid=EXECUTOR_UUID$/,
+          "type": "coop"
+        }
+      }
+    ]
   ],
 ];