Show AddCrossingKerbHeight for crossing without crossing

[Helium314]

With the recent changes to the crossing quests, AddCrossingKerbHeight is almost never asked because it requires a crossing tagged.
Since SC now tags crossing only for informal crossings, the quest will rarely show up when adding crossing details in SC only.

Proposed solution: skip the crossing requirement, or also ask if crossing:signals or crossing:markings are tagged.

[HolgerJeromin]

ref #5471

[westnordost]

Hmm, not sure why there was the check for crossing at all. After all, the quest is asked for any crossing, regardless of what is the value of crossing in the end. So, rather than to complicate the filter, I think it can simply be removed.

[westnordost]

Ah, well, the AddCrossingType quest was only asked for crossings that are not crossings with driveways. So, we should filter that out here, then.