[* DateTimeV2] Add support for modifiers within the extraction

[aitelint]

Currently, modifiers like "before", "around", "after"... are correctly handled only if they appear at the beginning/end of the extraction, e.g. "before 2pm", but are ignored when they appear within the extraction, e.g. "il y a à peu près un mois" (around a month ago).

Describe the solution you'd like Modifiers should be taken into account regardless of their position in the extracted text.