Converting Task to a Tree structure (#11117)

* added support for tree view

* nestedset added to handle tree based structure

* treeview ui added

* removed is_group dependency

* added validation while editing a group-task

* codacy fix

* BOM like filter added

* Added ui-test for treeview-task
diff --git a/erpnext/config/projects.py b/erpnext/config/projects.py
index a8514b2..b97e097 100644
--- a/erpnext/config/projects.py
+++ b/erpnext/config/projects.py
@@ -15,6 +15,7 @@
 				{
 					"type": "doctype",
 					"name": "Task",
+					"route": "Tree/Task",
 					"description": _("Project activity / task."),
 				},
 				{