Convert Wasabi client-side filters to binary

ConvertFilters.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.2</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="NBitcoin" Version="4.1.1.73" />
  </ItemGroup>

</Project>

Program.cs

using System;
using System.IO;
using System.Linq;
using NBitcoin.DataEncoders;

namespace BinaryFilters
{
    class Program
    {
        private static byte[] EmptyByteArray = new byte[0];

        static void Main(string[] args)
        {
            using(var binaryFile = File.Open("/home/lontivero/.walletwasabi/client/IndexMain.bin", FileMode.Truncate))
            using(var writer = new BinaryWriter(binaryFile))
            using(var textFile = File.OpenRead("/home/lontivero/.walletwasabi/client/IndexMain.dat"))
            using(var reader = new StreamReader(textFile))
            {
                string line;
                while((line = reader.ReadLine()) != null)
                {
                    var parts = line.Split(":", StringSplitOptions.RemoveEmptyEntries);
                    var blockId = Encoders.Hex.DecodeData(parts[0]).Reverse().ToArray();
                    var filter = parts.Length == 2 ? Encoders.Hex.DecodeData(parts[1]) : EmptyByteArray;

                    writer.Write(blockId);
                    writer.Write(BitConverter.GetBytes(filter.Length));
                    writer.Write(filter);
                }
            }
        }
    }
}