Whitelabelling: Override version in UI from config (#84392)

* Unify how the version is shown in the UI

* use versionString in dashboard help bundles

* fix lint

* remove comment

* fix test types

* make test less flakey

pkg/api/index.go

@@ -161,6 +161,7 @@ func (hs *HTTPServer) setIndexViewData(c *contextmodel.ReqContext) (*dtos.IndexV
 	hs.HooksService.RunIndexDataHooks(&data, c)
 
 	data.NavTree.ApplyAdminIA()
+	data.NavTree.ApplyHelpVersion(data.Settings.BuildInfo.VersionString) // RunIndexDataHooks can modify the version string
 	data.NavTree.Sort()
 
 	return &data, nil