HTTPS API ability to import PKI certificates `x.x.x.x/import`
```
vyos@r4:~$ import pki
Possible completions:
ca Import CA certificate into PKI
certificate Import certificate into PKI
crl Import certificate revocation list into PKI
dh Import DH parameters into PKI
key-pair Import key pair into PKI
openvpn Import OpenVPN keys into PKI
```
We have a limitation: we can't import certs without entering configuration mode and committing.
```
vyos@r4:~$ import pki ca myca file /config/auth/ca_ansible.crt
You are not in configure mode, commands to install manually from configure mode:
set pki ca myca certificate 'MXXXxxx=='
vyos@r4:~$
```