Add ad-hoc data serialization via yang modules
Add ad-hoc data serialization via yang modules

This will be used during the interim time where not all Snabb apps have
associated Lua schemas.

eugeneia/snabbswitch,alexandergall/snabbswitch,Igalia/snabbswitch,snabbco/snabb,SnabbCo/snabbswitch,heryii/snabb,heryii/snabb,alexandergall/snabbswitch,heryii/snabb,snabbco/snabb,Igalia/snabb,eugeneia/snabb,snabbco/snabb,heryii/snabb,Igalia/snabb,dpino/snabb,eugeneia/snabb,Igalia/snabbswitch,alexandergall/snabbswitch,alexandergall/snabbswitch,dpino/snabb,snabbco/snabb,eugeneia/snabbswitch,eugeneia/snabb,eugeneia/snabb,dpino/snabb,eugeneia/snabbswitch,eugeneia/snabb,SnabbCo/snabbswitch,dpino/snabb,Igalia/snabb,dpino/snabb,snabbco/snabb,Igalia/snabb,Igalia/snabb,Igalia/snabbswitch,alexandergall/snabbswitch,eugeneia/snabb,dpino/snabbswitch,heryii/snabb,dpino/snabb,alexandergall/snabbswitch,SnabbCo/snabbswitch,Igalia/snabb,SnabbCo/snabbswitch,heryii/snabb,dpino/snabb,eugeneia/snabbswitch,snabbco/snabb,snabbco/snabb,eugeneia/snabb,alexandergall/snabbswitch,snabbco/snabb,Igalia/snabb,dpino/snabbswitch,eugeneia/snabb,dpino/snabbswitch,alexandergall/snabbswitch,Igalia/snabbswitch,dpino/snabbswitch,Igalia/snabbswitch,Igalia/snabb