Rewrites a good amount of legality APIs pertaining to:
* Legal moves that can be learned
* Evolution chains & cross-generation paths
* Memory validation with forgotten moves
In generation 8, there are 3 separate contexts an entity can exist in: SW/SH, BD/SP, and LA. Not every entity can cross between them, and not every entity from generation 7 can exist in generation 8 (Gogoat, etc). By creating class models representing the restrictions to cross each boundary, we are able to better track and validate data.
The old implementation of validating moves was greedy: it would iterate for all generations and evolutions, and build a full list of every move that can be learned, storing it on the heap. Now, we check one game group at a time to see if the entity can learn a move that hasn't yet been validated. End result is an algorithm that requires 0 allocation, and a smaller/quicker search space.
The old implementation of storing move parses was inefficient; for each move that was parsed, a new object is created and adjusted depending on the parse. Now, move parse results are `struct` and store the move parse contiguously in memory. End result is faster parsing and 0 memory allocation.
* `PersonalTable` objects have been improved with new API methods to check if a species+form can exist in the game.
* `IEncounterTemplate` objects have been improved to indicate the `EntityContext` they originate in (similar to `Generation`).
* Some APIs have been extended to accept `Span<T>` instead of Array/IEnumerable
* Revises legality checks to account for traveling between the three game islands (PLA/BDSP/SWSH)
* Adds conversion mechanisms between the three formats, as well as flexible conversion options to backfill missing data (thanks GameFreak/ILCA for opting for lossy conversion instead of updating the games).
* Adds API abstractions for HOME data storage format (EKH/PKH format 1, aka EH1/PH1).
* Revises some APIs for better usage:
- `PKM` now exposes a `Context` to indicate the isolation context for legality purposes.
- Some method signatures have changed to accept `Context` or `GameVersion` instead of a vague `int` for Generation.
- Evolution History is now tracked in the Legality parse for specific contexts, rather than only per generation.
struct implementing interface is boxed when passed to method that accepts interface (not generic method).
Removes IDexLevel (no other inheritors but EvoCriteria) and uses the primitive the data is stored (array, not IReadOnlyList) for slightly better perf.
* Make EvolutionCriteria struct
8 bytes per object instead of 26
Unify LevelMin/LevelMax to match EncounterTemplate
bubble up precise array type for better iteration
* Inline queue operations, less allocation
* Inline some logic
* Update EvolutionChain.cs
* Improve clarity on duplicate move check
* Search reverse
For a dual stage chain, finds it first iteration rather than second.
* Reuses move parse result objects for each encounter parsed in a LegalityCheck attempt, instead of creating a new object.
* Ensures the objects are never-null, and makes cleanup easier.
Slightly adjusts some other parts of the moveset validation to reduce allocations.
