Fix(DexService->evos/prevo): Evos and prevo fields are not being parsed correctly

[favna]

Please describe the problem you are having in as much detail as possible:

It appears that the evos and prevo fields are not being parsed correctly because they are reported as null even on something like Ivysaur.

Include a reproducible code sample here, if possible:

fragment dexdetails on DexDetails {
  num species types
  abilities { first second hidden special }
  baseStats { hp attack defense specialattack specialdefense speed }
  gender { male female special }
  color eggGroups evolutionLevel evos prevo forme formeLetter
  height weight baseForme baseSpecies otherFormes
  sprite shinySprite smogonTier
  bulbapediaPage serebiiPage smogonPage
  flavorTexts { game flavor }
}

fragment evolutions on DexDetails {
  evolutions { ...dexdetails }
  preevolutions { ...dexdetails }
}

{
  getPokemonDetails(pokemon:melmetal) {
    ...dexdetails
    ...evolutions
  }
}

Further details:

• version: 1.0.1
• Node.js version: 12-LTS
• Operating system: Windows
• Priority this issue should have – please be realistic and elaborate if possible: High

• I have also tested the issue on latest master, commit hash: 97bb3ed