support add output for openlan provider

[danieldin95]

Add a vlxan type output:

openlan output add --network example --remote 1.1.1.2 --segment 100 --protocol vxlan

Add a gre type output:

openlan output add --network example --remote 1.1.1.2 --segment 100 --protocol gre

Add a vxlan type output:

openlan output add --network example --remote enp2s3 --segment 23

Remove a vxlan type output:

openlan output rm --network example --device vxn100

Display all outputs

openlan output list --network example

Add a openlan type output:

openlan output add --network example --protocol tcp --connection 1.1.1.1 --secret aes-128:key --auth user:password