Fix potential memory leaks

Arrays declared on a class are shared across instances and are globals (
availaible through the prototype ). A computed or observer that would
use it as a dependent key would prevent the object from being garbage
collected.
Do not add event handler if the view is destoyed.

As we add the event handler on the next run loop, it is possible for the
view to be destroyed before. This leads to memory leaks.
[Tests] Fix some tests

- Fix test dependencies
- Fix ColorPicker unit tests
- Fix findInMultiChosen to open the dropdown
- Fix Text editor component functional tests

More tests passing