Place label parsing is broken

[KuraiAndras]

Right now using the mapbox-streets-v7 and mapbox-streets-v8 tile-sets querying place labels throws excpetions when parsing properties. The exception happens when the API returns duplicated keys. For example for the class property it returns both country and disputed_country.

The problematic code is in VectorTileFeatures.cs GetProperties() method

public Dictionary<string, object> GetProperties()
{

    if (0 != Tags.Count % 2)
    {
        throw new Exception(string.Format("Layer [{0}]: uneven number of feature tag ids", _layer.Name));
    }
    Dictionary<string, object> properties = new Dictionary<string, object>();
    int tagCount = Tags.Count;
    for (int i = 0; i < tagCount; i += 2)
    {
        properties.Add(_layer.Keys[Tags[i]], _layer.Values[Tags[i + 1]]);
    }
    return properties;
}

Suggested fix:

public Dictionary<string, object> GetProperties()
{
    if (Tags.Count % 2 != 0) throw new InvalidOperationException($"Layer [{_layer.Name}]: uneven number of feature tag ids");
    var properties = new Dictionary<string, object>();
    var tagCount = Tags.Count;
    for (var i = 0; i < tagCount; i += 2)
    {
        var key = _layer.Keys[Tags[i]];
        var value = _layer.Values[Tags[i + 1]];

        if (properties.TryGetValue(key, out var oldValue))
        {
            if (Equals(value, oldValue))
            {
                continue;
            }
            else
            {
                // To work around the issue we started using this projects source directly in Unity. This logging should be different in the actual fix
                UnityEngine.Debug.LogWarning($"Overriding tile property. Key: {key}, Old value: {properties[key]}, New value: {value}");
            }
        }

        properties[key] = value;
    }
    return properties;
}