Adopt a standard naming convention and signture for debug functions

Adopt a standard naming convention and signture for debug functions

To get the "dd" debugger command to work without having to create an
wxplicit mapping from type to function either by hand or by runtime
inspection (the latter preventing setting up the command at debugger
startup), the debug functions that dd calls should have a type of
the form

    foo_debug(FILE *fp, foo_t const *)

We add the qualifier becausen
 * some support functions with extra parameters are meant to be
   called by these functions, which pass the additional parameters;
   the functions we do call can pass fp along, or in the case of
   src/lib/util/dict_print.c, add fp to the context
 * fe_dict_attr_t * has three debug functions
 * fr_pair_validate_debug() takes a pointer to an array, and
   thus can't follow the convention
 * virtual_server_{listen, process}_debug() and module_rlm_list_debug()
   have *no* parameters