db-parser: rename _r_find_node to _find_node_recursively()

Signed-off-by: Balazs Scheidler <balazs.scheidler@balabit.com>
db-parser: extract add_parser_match_debug_info function

Signed-off-by: Balazs Scheidler <balazs.scheidler@balabit.com>
db-parser: remove whole_key argument from r_find_node()

Signed-off-by: Balazs Scheidler <balazs.scheidler@balabit.com>