Before converting services CLI config to `get_config_dict()` and reuse already present templating - and probably tests (after T2936 was migrated) - the CLI should be streamlined to match the PPPoE implementation.
The difference is, one side calls it ppp-options, the other calls the CLI node ppp-settings. Both perform the same stuff but under different nodes - which won't work when using `get_config_dict()`.
Catch-all task for all Accel-PPP service CLI migrations
* PPPoE
* rename `local-ip` to `gateway-address`
* SSTP
* move `network-settings gateway-address` to `gateway-address`
* move `network-settings name-server` to `name-server`
* move `network-settings mtu` to `mtu`
* drop ` network-settings` node