Many updates in the SOO framework

The master branch has been deeply updated with major uprades such as QEMU 5.2.0, and 64-bit support in AVZ and agency. MEs are still in 32-bit, but will be upgraded still during this Year.
SOOlink has been refactored at different levels, but now a major change is the presence of the soo_env structures which enable to launch several instances of SOO devices in the same emulated environment. However, this feature is helpful only for basic testings from the DCM to plugins, but without ME migration; it has been developed to validate further network topologies (the configuration of such a topology remains to be done).