#6423 port port BeakerX tree panel to Lab (#6711)

* #6423 expose full bootstrap styles for lab, and fix font path issue

* #6423 Create and register BeakerxTree JupyterLabPlugin

* #6423 BeakerXTreeWidget - recreate layout using "@phosphor/widgets" Panel

* #6423 BannerWidget - implementation using "@phosphor/widgets"

* #6423 SyncIndicatorWidget

* #6423 JVMOptionsWidget

* #6423 BeakerxApi and Urls for BeakerxTree

* #6423 add overflow to Widget

* #6423 remove unused code

* #6423 DefaultOptionsWidget, DefaultOptionsModel and HeapGBValidator

* #6423 PropertiesWidget, PropertiesModel

* #6423 SyncIndicatorWidget

* #6423 Messages

* #6423 OtherOptionsWidget, OtherOptionsModel

* #6423 BeakerxApi

* #6423 BeakerxApi JVMOptionsWidget

* #6423 Restore widget state on reload

* #6423 change => keyup

* #6423 change command label

* #6423 wip

* #6423 move tree source from js/lab to js/notebook

* #6423 packages, tsconfig, jquery

* #6423 fix compilation errors

* #6423 working tree widget in notebook

* #6423 remove not needed files

* #6423 remove paths from .gitignore

* #6423 use BeakerXTreeWidget in lab

* #6423 fix missed baseUrl TODO; BeakerxApi => BeakerXApi; fix NaN showing when changing heap size to empty string

* #6423 fix

beakerx/.gitignore

@@ -1,5 +1,3 @@
 /build/
 /.classpath
 /.project
-!/beakerx/static/tree.js
-!/beakerx/static/img/