Added DB backup command

Added automated backup every 1 hour

Services/HandleDbBackup.cs

@@ -0,0 +1,24 @@
+using JsonFlatFileDataStore;
+using Microsoft.Extensions.Logging;
+using mstdnCats.Models;
+using Telegram.Bot;
+using Telegram.Bot.Types;
+using Telegram.Bot.Types.Enums;
+
+namespace mstdnCats.Services;
+
+public class HandleDbBackup
+{
+    public static async Task HandleDbBackupAsync(TelegramBotClient _bot, ILogger<MastodonBot>? logger, string dbname, string adminId,IDocumentCollection<Post> _db)
+    {
+        logger?.LogInformation("Backup requested");
+        
+        await using Stream stream = System.IO.File.OpenRead("./" + dbname);
+        var message = await _bot.SendDocumentAsync(adminId, document: InputFile.FromStream(stream, dbname+".json"),
+            caption: "Backup of " + dbname + "\nCreated at " + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss" + "\nCurrent post count: " + _db.AsQueryable().Count()), parseMode: ParseMode.Html);
+
+        logger?.LogInformation("Backup sent");
+
+
+    }
+}