In-chassis Junos node slicing: Multiversion software support

In-chassis Junos Node Slicing supports multi-version software compatibility, enabling the BSYS to interoperate with a guest network function (GNF), which runs a Junos OS version that is earlier or later than the software version on the base system (BSYS). This feature supports a difference of up to two versions between the GNF and the BSYS. That is, the GNF software can be up to two versions earlier or later than the BSYS software.