get_options() and num_options used to work on all menu items, including
blank spaces and headers. Now these work only on options, as they were
originally intended
cli_select_item() allows to quickly launch a menu from code, but if only
a single item is given a selection is not necessary in most cases.
Therefore we now instantly return the given value in these cases. This
can be turned off by setting return_single=False
This uses prompt-toolkit's builtin search functionality to search
through the buffer representing the menu, allowing the user
to navigate faster through the entries
Sebastian Lohff