`PaginatedTripLoader`: Use `TimeTimetabledTime` of first `timedLeg` instead of `StartTime`

[r3to]

StartTime of a Trip respects the EstimatedTime. This could lead to ignored trip when using that value in the PaginatedTripLoader

[TO-mdv]

@r3to ist dieser Issue behoben oder noch offen ?

[r3to]

@TO-mdv Noch offen