Change return type of GetComponent

Version - v1.2 (ysfchn#7)

* Main code update

* Add build.xml from mit-cml/extension-template

* Add libraries from mit-cml/extension-template

* Fix Errors

* Main code update - 2

* Remove GitHub Action

As version 1.2 switches to MIT's extension template, this action won't work anymore, so it is better to delete it for now.

* Make SetProperty block more stable

* Disable RemoveAll block for now

Public source released