Handle combat effects of surprise attacks that don't allow for a full defense

[phylll]

Surprised targets of attacks do not get to defend, but still suffer -- potentially lethal -- effects that need to be recorded properly. The defense script or a version of it should be able to handle this edge case.

[phylll]

Quick review of defense code says this should be doable by injecting a bunch of conditional blocks that executes the actual defense logic only if the noDefense flag (whatever it will be called) is not present.

Research question: How about health <= 3, aren't those tokens equally defenseless? Are we handling this case properly so far? -- No, we have not. According to Kodex:64, less than 4 health points means that someone is incapacitated and doesn't get a defense at all.

So, when does the target of an attack not get a defense roll?

• If health is below 4.
• If endurance is 0.
• If the attack is a complete surprise, which could be
  • either stored in an attack modifier for a "defenseless target" selected accordingly in the melee attack script, which needs to be passed along to the defense script,
  • or manually entered (because the ranged attack script doesn't now about defenseless targets, and there may be other special cases or magic spells etc.)

In those cases, the player should not even need to enter various pointless modifiers for a roll that is not being made. Since we cannot build logical forks between scripts (because Roll20 doesn't evaluate user input in scripts dynamically called through !mmm chat: %{char|ability}), the way to do this is to pull the defensibility determination back into all kinds of attack scripts. To cover all use cases, that means:

1. Any attack script can determine the target's health or endurance being at defenseless levels (a new game-public function would be useful here);
2. meleeAttack already has the player select a modifier if they attack an otherwise defenseless target;
3. rangedAttack doesn't but could add such a modifier easily;
4. our magic script doesn't, either, but it could;
5. and finally, we could build a very simple wrapper to call in any other weird case of defenselessness.

So, these four attack scripts (no. 2 through 5, above) would check for health/endurance and the player's manual determinations and as a result either call the main defense script directly (if no further input is necessary because there won't be a real defense), or a customize wrapper to collect defense modifiers and then call the main defense script to do its thing.

Or, we simply offer players a "defenseless" option for every call, and that's it.

[phylll]

Closed via https://github.com/michael-buschbeck/mychs-macro-magic/pull/188