Add ORS Duo product to simpleran SR

ORS Duo is an ORS with two SDR boards, this MR adds supports for this new product by adding a "software-ors-duo.cfg" software buildout, it aims to make ORS Duo management as similar as possible to the classic ORS.

Here are the different modes supported by ORS Duo:

• 4x4 MIMO: supported, user just has to change the number of DL antennas and UL antennas
• Carrier aggregation: supported, user has to set "enable_ca" parameter and all cell related parameters are duplicated in the input parameter JSON
• 5G NSA: not supported yet in the SR
• UE + eNB / gNB: not supported yet in the SR

This MR also adds two commits to prepare the integration of ORS Duo, and an unrelated commit on websocket URL publication.

/cc @tomo @kirr @lu.xu