Rewrite random YANG path selector and value generator
Rewrite random YANG path selector and value generator

The path selector and value generator now use the grammar instead of the
schema.  Invalid path and value generation are now parameterized by a
function argument instead of being a global variable.

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