Just as special tokens are replaced in debriefings, replace them in command briefings and briefings as well.
Change `string_replace_tokens_with_keys` to `message_translate_tokens` (since it's the same thing) and add a `replaceContainers` script API function to complement `replaceVariables` and `replaceTokens`.
Also replace every category of token in `sexp_modify_variable` and add comments to places where token replacement might be expected but happens elsewhere.
This maintains the type information which can be used for enforce
const-correctness and also for implementing more advanced ways of
handling the type information.
This converts the previous int handles to a strongly-typed wrapper
handle which will make the API more self-documenting and will ensure
that wrongly used handles are detected at compile time.
I already found a few mistakes with these changes which I also fixed
here.
Goober5000