NavTree: Make it possible to configure where in nav tree plugins live (#55484)

* NewIA: Plugin nav config

* progress

* Progress

* Things are working

* Add monitoring node

* Add alerts and incidents

* added experiment with standalone page

* Refactoring by adding a type for navtree root

* First test working

* More tests

* more tests

* Progress on richer config and sorting

* Sort weight working

* Path config

* Improving logic for not including admin or cfg nodes, making it the last step so that enterprise can add admin nodes without having to worry about the section not existing

* fixed index routes

* removed file

* Fixes

* Fixing tests

* Fixing more tests and adding support for weight config

* Updates

* Remove unused fake

* More fixes

* Minor tweak

* Minor fix

* Can now control position using sortweight even when existing items have no sortweight

* Added tests for frontend standalone page logic

* more tests

* Remove unused fake and fixed lint issue

* Moving reading settings to navtree impl package

* remove nav_id setting prefix

* Remove old test file

* Fix trailing newline

* Fixed bug with adding nil node

* fixing lint issue

* remove some code we have to rethink

* move read settings to PrivideService and switch to util.SplitString

pkg/api/dtos/index.go

@@ -15,7 +15,7 @@ type IndexViewData struct {
 	GoogleAnalyticsId       string
 	GoogleAnalytics4Id      string
 	GoogleTagManagerId      string
-	NavTree                 []*navtree.NavLink
+	NavTree                 *navtree.NavTreeRoot
 	BuildVersion            string
 	BuildCommit             string
 	Theme                   string