feat: validate mods compatibility when trying to load saved games

[LordMidas]

• We save the mod compatibility data for registered mods using the same technology that is available in Modern Hooks.
• We then validate the saved mods just like Modern Hooks validates installed mods.
• We allow mods to adjust the saved mods' compatibility data during validation in case they want to act as a compatibility patch or fork.

Usage

This system is meant to seamlessly blend with Modern Hooks. Use Modern Hooks and declare your requirements/conflicts as normal. This info will be saved to the save file and will be automatically used to validate compatibility.

Declaring your mod as unsafe to add to existing saves

Use Modern Hooks and require your own mod i.e.

HooksMod.require("my_own_mod_id");

Declaring your mod incompatible with older versions of itself

Use Modern Hooks and require a version of your mod:

HooksMod.require("my_own_mod_id >= 0.5.5");

Applying a compatibility patch to remove declared incompatibilities

During savegame compatibility validation, you can adjust the CompatibilityData stored in the save file. For this, you need to use the MSU Serialization system. This can be useful when creating compatibility patches or creating forks of mods with different ids and declaring yourself compatible with save games that require the original mod.

// Let's say the save file has `mod_a` which requires `mod_b` version 1.8.0 or greater.
// You made a compatibility patch mod which can drop this requirement, or reduce the requirement to 1.5.0.
MyMSUMod.Serialization.onValidateSavedMods( _modsInfo )
{
  if (_modsInfo.hasMod("mod_a")
  {
    // First clear the compatibility data e.g. requirement/conflict stored for `mod_xyz` about `mod_asdf`.
     _modsInfo.clearCompatibilityData("mod_a", "mod_b");
   // Then you can add new requirement/conflict e.g.
    _modsInfo.getMod("mod_a").require("mod_b >= 1.5.0");
  }

[Darxo]

The 3 should be a static class variable with a name. Especially since you later use a [3] magic number a second time where it is not clear if both of those values mean the same thing

[Darxo]

4 should be a static class variable

[Darxo]

Perhaps it's possible to adjust the vanilla warning message that's displayed on those incompatible savegames.
Make it include "Mods" too.
- Incompatible Version or DLC/Mods Missing -