tests REFACTOR simplify using customizable input handler
tests REFACTOR simplify using customizable input handler

avoid need for input handler initiation in every test function. Instead,
use combination of the setups and global variable.

sartura/libyang,CESNET/libyang,sartura/libyang,sartura/libyang,sartura/libyang,sartura/libyang,sartura/libyang,CESNET/libyang