Add playbook conversion tool to SOARCA

[MaartendeKruijf]

Is your feature request related to a problem? Please describe.
CACAO v2 is a relative new standard, to kickstart CACAOv2 playbook development a conversion tool is needed to covert current BPNM or other formatted playbooks into CACAOv2

Describe the solution you'd like
To start integrating this capability a command line tool to convert various playbooks like BPNM, Splunk SOAR etc.

For BPNM there is already a tool we could try to take inspiration from that: https://github.com/cydarm/bpmn-to-cacao

Spunk playbook examples can be found here: https://github.com/phantomcyber/playbooks