Improve recipe cleansing/pre-processing to mitigate poor data quality

[Quaffel]

In addition to the data quality issues described in #50, some further problems pop up when carefully inspecting the results.

• Complete recipes with zeroed out ingredient quantities

  • Monkey Gland
  • 0ml absinthe
  • 0ml grenadine
  • 30ml orange juice
  • 50ml gin
  • Ramos Gin Fizz
  • 30ml syrup
  • 30ml syrup
  • 60ml cream
  • 15ml lemon juice
  • 15ml lime juice
  • 30ml egg white
  • 3ml orange flower water
  • 45ml gin
  • 0ml vanilla extract

• Complete recipes with duplicate ingredients

  • Ramos Gin Fizz
  • 30ml syrup
  • 30ml syrup
  • 60ml cream
  • 15ml lemon juice
  • 15ml lime juice
  • 30ml egg white
  • 3ml orange flower water
  • 45ml gin
  • 0ml vanilla extract
  • Suffering Bastard
  • 15ml lime juice
  • 30ml gin
  • 30ml brandy
  • 30ml brandy
  • 2ml Angostura bitters

• Recipes with only a single ingredient (relates to #40)

  • El Presidente
  • 1ml grenandine

[Quaffel]

Current state of the investigation:

• Complete recipes with zeroed out ingredient quantities
  • Monkey Gland: Ingredients are of unit "drop" which are directly converted into 0.05 milliliters (per drop)
  • Ramos Gin Fizz: Same issue as for "Monkey Gland"
• Complete recipes with duplicate ingredients
  • Ramos Gin Fizz: The problematic ingredient appears only once in Wikidata. There must be some sort of issue in the query and/or its handling. Interestingly enough, the "Gin Fizz" cocktail suffers from the same issue. Even though both cocktails have more ingredients in common, "syrup" is the only one that appears twice.
  • Suffering bastard: Same issue as for "Ramos Gin Fizz"

What catches the eye is that for the duplicate ingredients, the name of the ingredient is not only an ingredient but also a category.