Add 'block user' option to the report window

app/soapbox/locales/defaultMessages.json

@@ -2700,6 +2700,14 @@
       {
         "defaultMessage": "Forward to {target}",
         "id": "report.forward"
+      },
+      {
+        "defaultMessage": "Do you also want to block this account?",
+        "id": "report.block_hint"
+      },
+      {
+        "defaultMessage": "Block {target}",
+        "id": "report.block"
       }
     ],
     "path": "app/soapbox/features/ui/components/report_modal.json"
@@ -2894,4 +2902,4 @@
     ],
     "path": "app/soapbox/features/video/index.json"
   }
-]
+]

app/soapbox/locales/en.json

@@ -325,6 +325,8 @@
   "relative_time.minutes": "{number}m",
   "relative_time.seconds": "{number}s",
   "reply_indicator.cancel": "Cancel",
+  "report.block": "Block {target}",
+  "report.block_hint": "Do you also want to block this account?",
   "report.forward": "Forward to {target}",
   "report.forward_hint": "The account is from another server. Send an anonymized copy of the report there as well?",
   "report.hint": "The report will be sent to your server moderators. You can provide an explanation of why you are reporting this account below:",