Improve Meal count heuristics

[ursjoss]

Adjust FilterExpressionProvider for MitiMealType.

• contains "Hauptsp"
• starts with "Menü"
• starts with "Praktika"

Check for more improvements

[ursjoss]

As Meal, we need to also consider:

• "Menu (nur Hauptgang)"
• "2-Gang-Menu (mit Vorspeise oder Dessert)"
• "3 Gang-Menu (mit Vorspeise + Dessert)"
• "Seniorenmittagstisch"

For Children, we need to consider:

• "Kinder-Teigwaren"
• "Kindermenu (kleiner Hauptgang, bis 12 Jahre)"