[* DateTimeV2] Modifiers incorrectly included in recognized Set mentions

[aitelint]

In certain cases, SetExtractor wrongly considers parts of the input as belonging to the extracted entities. For example:

• "it is the same every year" returns "same every year" instead of "every year",
• "I do that each week" returns "that each week" instead of "each week",
• "They finish early every morning" returns "early every morning" instead of "every morning",
• "In September every 2 days the doctor went to check the patient." returns "september every 2" instead of "every 2 days".

This can produce completely wrong results like in the last example which is resolved to "every September 2" instead of "every 2 days".