Rename wEvosMoves and get rid of MAX_EVOLUTIONS and EVOLUTION_SIZE

[Rangi42]

This buffer is a misnomer. It's only used to store evolution data for drawing the evolution stone Able/Not Able within RedrawPartyMenu_ (engine/menus/party_menu.asm). It's not used to store level-up moves. Its size of 13 is a just large enough for Eevee's three 4-byte evolutions plus a 0 terminator. There's no consistent "evolution size"; for example, the current buffer would allow a mon to have four evolutions by level-up, since each of those is only three bytes.