bigip_device_certificate transport mode through REST

[fchmainy]

the bigip_device_certificate only works through SSH. In our case SSH is not allowed to the BIG-IPs because it is forbidden per our security policy.

We need to use REST transport as a second choice for transport.

thank you very much.

[trinaths]

created INFRAANO-562 for internal tracking.

[pgouband]

After discussing with @fchmainy, closing this now.