TestData: Remove references to TestData "DB" (#62603)

* remove refs testdatadb

* fix trailing semi-colon

* remove pluginName completely

devenv/dev-dashboards/feature-templating/templating-textbox-e2e-scenarios.json

@@ -5,8 +5,7 @@
       "label": "gdev-testdata",
       "description": "",
       "type": "datasource",
-      "pluginId": "testdata",
-      "pluginName": "TestData DB"
+      "pluginId": "testdata"
     }
   ],
   "__requires": [
@@ -19,7 +18,7 @@
     {
       "type": "datasource",
       "id": "testdata",
-      "name": "TestData DB",
+      "name": "TestData",
       "version": "1.0.0"
     },
     {