will always have latest data related to that type of node. Also, fixed
the cache_level for different node types.
This commit also contains fixes for the following issue:
* In extension module - use the 'node-list-by-name' instead of using a
  custom 'node-ajax-options' control, and removed redundant template
  schemas from it.
* When we tries to destroy the select2 object from
  Select2Cell/Select2Control while releasing the properties view,
  sometimes select2 can not find the instance related it for some
  unknown reason. Hence - before removing it we will check for manual
  instance existance using $.data('select2').
* When we traverse through the browser tree nodes very quickly, it tries
  to remove the object before it gets created completely, and results
  into an exception.
* Icon in the select2 drop down list was not visible due to some CSS
  issues.
Apart of that, we will generate two new browser events -
'pgadmin-node:created:<NODE-TYPE>', 'pgadmin-node:updated:<NODE-TYPE>'
whenever a new node is created, or an existing node will be updated.
						
					
				
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|---|---|---|
| .. | ||
| pgadmin | ||
| regression | ||
| babel.cfg | ||
| config.py | ||
| pgAdmin4.py | ||
| setup.py | ||