gpgconf: Fix --list-options for forced options
* tools/gpgconf-comp.c: Remove assert.h and replace all assert calls by log_assert. (known_options_gpg): Add "keyserver" as invisible. Remove "options". (known_pseudo_options_gpg, known_pseudo_options_gpgsm): New. (gc_component): Add field known_pseudo_options. (struct read_line_wrapper_parm_s): New. (read_line_wrapper): New. (retrieve_options_from_program): Use read_line_wrapper to handle pseudo options. (retrieve_options_from_program): Ignore to be ignored options. Add failsafe code to avoid calling percent_escape with NULL.
Due to reading the list of options from the argparser of the
component, we had no more information about the pseudo options and
thus could not emit them. Well, there is just one pseudo option right
now, but with this change we have a generalized concept for them:
Pseudo options are used to convey information from a component to
gpgconf; for example build-in values.
This is a combined backport of patches to master.