Feature: support multiple checks for healthchecks widget (#2580)

* Change healthchecks online/offline with the original up/down

* Add group statistics to healthcheck widget

* Update healthchecks docs

---------

Co-authored-by: shamoon <4887959+shamoon@users.noreply.github.com>

public/locales/en/common.json

@@ -491,9 +491,9 @@
     },
     "healthchecks": {
         "new": "New",
-        "up": "Online",
+        "up": "Up",
         "grace": "In Grace Period",
-        "down": "Offline",
+        "down": "Down",
         "paused": "Paused",
         "status": "Status",
         "last_ping": "Last Ping",