Panels: Add support for panels with no padding (#20012)

* Panels: Added support to set panel padding to zero

* WIP: fullChromeControl work

* Tweaks to header position

* Reverted some overlay mechanic and now back to no title only

* Fixed test

* Fixed transparent flag

* Added show title

* Added font weight to value

* Reverted back to no padding option

* Fixed issue with border and width and height

devenv/datasources.yaml

@@ -20,8 +20,8 @@ datasources:
     url: http://localhost:3011
 
   - name: gdev-testdata
-    type: testdata
     isDefault: true
+    type: testdata
 
   - name: gdev-influxdb
     type: influxdb