Achievements: add support for time constraints

[jbytheway]

Summary

SUMMARY: Features "Achievements can now have time constraints"

Purpose of change

It is common for achievements in games to require you to do something within a certain amount of time. We want to support that use case. Moreover, we would like to support achievements with a lower time bound (like "survive for a month").

Describe the solution

A new field "time_constraint" on achievements that allows enforcing a lower or upper bound on the time an achievement can be captured (but not both).

Comes with the following associated changes:

• There's a new calendar::start_of_game to keep a record of when the game started for reference. In legacy saves this will default to start_of_cataclysm.
• Upper bounds on statistics in achievement requirements.
• A concept of "failed" achievements when it becomes provable that an achievement is impossible of the rest of the game (in most cases this will be because it had a time constraint and that time has passed).
• Make score descriptions optional. When the underlying statistic has a description, use that in a reasonable default format.
• Move achievements to a new, separate, json file since the scores.json was starting to get cluttered.
• If you have completed an achievement then the achievements tab now tells you when you did.
• Added a new achievement for killing a monster in the first minute of the game to test these features.

Describe alternatives you've considered

One limitation is that you can't directly write an achievement which fires at a particular time. Achievements are only considered when a relevant event fires. So if you want to write e.g. a "survive for a month" achievement then it still needs to have an associated event (via a statistic), and won't fire until that event happens. We could add (or link into) a timer system for additional triggers beyond events, but I think that's not really necessary.

Testing

Added some new unit tests.

Tested in game long enough to capture the below screenshots.

Additional context

(The pictures below have an off-by-one error in the day of printed times; I fixed that after taking the screenshots).

How things look initially:

Getting both achievements by killing a zombie fast:

Achievements window now looks like:

If instead you wait until after a minute then:

And then, after killing a zombie:

[kevingranade]

achievments_tracker

  kills

-------------------------------------------------------------------------------

stats_tracker_test.cpp:240

...............................................................................

stats_tracker_test.cpp:286: FAILED:

  CHECK( a.ui_text_for( achievements_completed.at( a_kill_zombie ) ) == "<color_c_light_green>One down, billions to go…</color>\n" "  <color_c_light_green>Completed Year 1, Spring, day 1 0010.00</color>\n" "  <color_c_green>1/1 Number of zombies killed</color>\n" )

with expansion:

  "<color_c_light_green>One down, billions to go…</color>

    <color_c_light_green>Completed Year 1, Spring, day 1 12:10:00AM</color>

    <color_c_green>1/1 Number of zombies killed</color>

  "

  ==

  "<color_c_light_green>One down, billions to go…</color>

    <color_c_light_green>Completed Year 1, Spring, day 1 0010.00</color>

    <color_c_green>1/1 Number of zombies killed</color>

  "

with message:

  time_since_game_start := {?}

[kevingranade]

Suggested by clang-tidy readability-simplify-boolean-expr

Suggested change

	if( equals_statistic_ && ( *equals_statistic_ )->monotonicity() != monotonically::constant ) {
	return false;
	}
	return true;
	return !equals_statistic_ || ( *equals_statistic_ )->monotonicity() == monotonically::constant );