Feature/pet name gender

[matheusgondra]

Updating the /pet route with the petName and gender fields.

The gender of the pet is only saved in the database as an "M" or "F" character. I tried to use an enum in prisma, but it was breaking everything and it was a lot of work to fix everything. So I decided to type it as a string and in the route validator I did the check

// omitted
const gender = input[this.fieldName].toUpperCase()

    if (typeof gender !== 'string') {
      return new InvalidParamError(this.fieldName)
    }

    if (!['M', 'F'].includes(gender)) {
      return new InvalidParamError(this.fieldName)
    }
// omitted