OTB plugin integration in QGIS >= 3.22

Target documentation resources

CookBook shall be updated to document recent QGIS changes in OTB plugin integration : https://www.orfeo-toolbox.org/CookBook/QGISInterface.html

Change requested

QGIS 3.22 does not activate any more OTB plugins (and some others) by default. As OTB plugin is an official plugin, it only needs to be activated (in the Plugins>Manage plugins menu) and then configured (as it used to be, in the Settings>Options menu).

This is a small change but users need to know how to reactivate OTB plugin.

Tests have been done on Ubuntu 20.04 / QGIS 3.22 RC / OTB 8.0a1 and it works fine.