Add support form multiple different "explorer-like" tree representations

[pcdavid]

In the sirius-components-collaborative-trees most of the code is generic, but TreeEventProcessorFactory is hard-coded to support a single TreeDescription source, namely IExplorerDescriptionProvider.

For the various modals we will need for the reference widget (see #2116, #2117, #2118) we will need tree representations which use a different TreeDescription definition.

TreeEventProcessorFactory and the related code (both back and front) should be made more configurable to support for multiple TreeDescription definitions, so that the modals can use/subscribe to tree definitions adapted to their case.