Separate surface fields for segregated cycleways

[RudyTheDev]

It would be useful if highway=cycleway + segregated=yes could at least recognize and may be offer cycleway:surface= and footway:surface= instead of just surface. It's pretty common for these to have different surfaces (e.g. asphalt cycle part and paving stone pedestrian part segregated by a tactile strip).

I realize this likely needs code change in iD itself, but for now I only filed this issue here and not the main repo.

[tyrasd]

I realize this likely needs code change in iD itself

This would be possible to implement using the prerequisiteTag functionality: a field for cycleway:surface would have the following to only show up for segregated foot/cycleways.

"prerequisiteTag": {
    "key": "segregated",
    "value": "yes"
}

[matkoniecz]

This should also appear on highway=path with bicycle=designated

footway:surface for ones with foot=designated also would be useful

[matkoniecz]

This would be especially useful as some people using iD damage existing data due to being unaware that ways are having info about cycleway surfaces.