Feature: UrBackup Widget (#1735)

* Add initial UrBackup widget with counts of ok, errored, and out-of date clients

* Add configurable number of days since last backup before a client is considered out-of-date

* Don't count a lack of recent (or error free) image backup if image backup isn't supported.

* Add support for reporting total disk usage

* add support for "fields" from services.yaml

* fix field filtering, syntax

* Consolidate urbackup code, syntax changes

* Revert pnpm changes

* re-add urbackup-server-api

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

package.json

@@ -34,6 +34,7 @@
     "swr": "^1.3.0",
     "systeminformation": "^5.17.12",
     "tough-cookie": "^4.1.2",
+    "urbackup-server-api": "^0.8.9",
     "winston": "^3.8.2",
     "xml-js": "^1.6.11"
   },