feat: export guilds from old bot and import into new one

Catalogger.GoImporter/Program.cs

@@ -0,0 +1,56 @@
+// See https://aka.ms/new-console-template for more information
+
+using System.Text.Json;
+using Catalogger.Backend;
+using Catalogger.Backend.Database;
+using Catalogger.Backend.Extensions;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Configuration;
+using NodaTime;
+using NodaTime.Serialization.SystemTextJson;
+using NodaTime.Text;
+using Serilog;
+using Serilog.Events;
+using Serilog.Sinks.SystemConsole.Themes;
+
+namespace Catalogger.GoImporter;
+
+internal class Program
+{
+    public static JsonSerializerOptions JsonOptions =
+        new JsonSerializerOptions().ConfigureForNodaTime(
+            new NodaJsonSettings
+            {
+                InstantConverter = new NodaPatternConverter<Instant>(InstantPattern.ExtendedIso),
+            }
+        );
+
+    public static async Task Main(string[] args)
+    {
+        Log.Logger = new LoggerConfiguration()
+            .Enrich.FromLogContext()
+            .MinimumLevel.Debug()
+            .MinimumLevel.Override("Microsoft", LogEventLevel.Information)
+            .WriteTo.Console(theme: AnsiConsoleTheme.Sixteen)
+            .CreateLogger();
+
+        var config = new ConfigurationBuilder().AddConfiguration().Build().Get<Config>();
+        if (config == null)
+        {
+            Log.Fatal("No configuration object was created");
+            return;
+        }
+
+        var db = new DatabaseContext(config, null);
+        await db.Database.MigrateAsync();
+
+        var type = args[0].ToLowerInvariant();
+        var file = args[1];
+
+        if (type == "guilds")
+        {
+            Log.Information("Importing guilds from {File}", file);
+            await GuildImport.DoImportAsync(db, file);
+        }
+    }
+}