Increase number of supported targets and hosts in RTA

This work item covers increasing the RTA HW capacity for supporting directly a larger number of boards. The previously used 30-slot system is to be added to the current 60-slot system. The two systems can be separate also performing different tasks if that is considerably easier, for instance the older 30-slot system performing auto-validation of QBSPs. We may need even 4 copies of the same board type in RTA, and sometimes 2 will suffice so expanding the current capacity by 50% would help in supporting a slightly larger number of boards.

Current CI testing covers unit tests but with Qemu only (apart from Apple M1 Macs for Mac on ARM).