npctalk: add true/false responses and CONDITION trials to JSON

[mlangsdorf]

Summary

SUMMARY: Infrastructure "npctalk: add true/false responses and CONDITION trials to JSON"

Purpose of change

Fixes #27637 - response snippets will now be logged in their final form
Fixes #27397 - CONDITION trials was the last remaining requested feature
Add two new options for PC responses to NPC dialogues in JSON:

• a true/false conditional text, so the player has different response texts depending on a condition, but the same trial/effects/next topic
• a new CONDITION trial, so the player has a single response text, but the effects/next topic change depending on a binary condition

Of course, both these options can be combined.

Also, clear a bug where snippets in a response line were logged in their original form instead of their expanded form.

Describe the solution

Add new fields to talk_response, truetext, falsetext, and truefalse_condition. Add code to the JSON parser to populate these fields if a truefalsetext object is present. When creating an option line, set the text field to the truetext if the truefalse_condition is true and the falsetext otherwise.

Log the final version of the response text after parsing, not the original form.

Add a new type of trial, CONDITION. A CONDITION trial takes a condition field instead of a difficulty field, and sets the chance of the trial passing at 100 if the condition is true and at 0 otherwise.

Update the test cases to use a helper function that calls create_option_line() so that the truefalse_condition will be evaluated.

Additional context

Includes #27706

[kevingranade]

Spawned in a pair of NPCs, mind controlled both of them, then tried to talk to one to set it as the overseer, then it crashed on this line.
The way it crashed I can't get the backtrace.

I had also merged #27706.

[mlangsdorf]

Ah, this was something I'd fixed in the final version but didn't make it into the refactoring for submission.

Fixed.