Add `UINT64_T_ARG` and `INT64_T_ARG` macros for printf arguments, similar to `SIZE_T_ARG` and `PTRDIFF_T_ARG`.
In the process, fix some issues with the toolchain: in certain CI runs the toolchain headers were being #included multiple times, and certain CI runs produced collisions between clang definitions and gcc definitions. Resolve these issues with `#pragma once` and preprocessor guards in the event of both gcc and clang being active.
Also remove toolchain.h from sexp_container.cpp since it is already #included via pstypes.h.
* add node subtype for container names
* clean up and port changes to qtFRED
* fix parsing when container is the last argument
* fix serializing container name nodes
* fix parsing again
* disallow spaces in container names
* check for spaces and & chars while parsing container names
* early WIP for trying to get list containers of strings working as argument options
* indicate which SEXPs will be supported for now
* clean up
* add FRED/qtFRED support
* remove [in]validate-argument from supported SEXPs
* support map containers with string keys
* update FRED and qtFRED
* clean up
* update FRED help text
* revert some unneeded changes
* fix style
* remove added assertion
* backport useful changes from PR #4263 and then some
* clean up backport
* move condition_node evaluation outside of argument loop
* fix does_blank_of_op_support_container_args()
* fix assertion
* add OPF_DATA_OR_STR_CONTAINER and use restore old behavior of OPF_ANYTHING
* revert some unnecessary changes
* fix CI
* detect attempts to modify container while it is being used as special argument (WIP)
* evaluate conditional for each loop
* update placeholder text for new SEXP arg type
* finish/clean up
Goober5000