Enhancement: support different bytes multipliers for disk space for resources / glances and metrics widgets (#2966)

docs/widgets/services/glances.md

@@ -18,6 +18,7 @@ widget:
   username: user # optional if auth enabled in Glances
   password: pass # optional if auth enabled in Glances
   metric: cpu
+  diskUnits: bytes # optional, bytes (default) or bbytes. Only applies to disk
 ```
 
 _Please note, this widget does not need an `href`, `icon` or `description` on its parent service. To achieve the same effect as the examples above, see as an example:_