feat(envelope): Envelopes-Datenquelle und Initialisierung angepasst

- `EnvelopeTypeService` und `EnvelopeTypeController` hinzugefügt, um Envelope-Typen im Cache zu speichern und bereitzustellen.
- `ConfigurationService` erstellt und mit `APP_INITIALIZER` konfiguriert, um Envelope-Typen bei der Anwendungserstellung zu laden.
- `EnvelopeTableComponent` aktualisiert, um Envelope-Typen aus der Konfiguration zu verwenden, anstatt hartkodierte Werte zu nutzen.

EnvelopeGenerator.Application/Services/EnvelopeTypeService.cs

@@ -1,19 +1,31 @@
 using AutoMapper;
 using DigitalData.Core.Application;
-using Microsoft.Extensions.Localization;
 using EnvelopeGenerator.Application.Contracts;
 using EnvelopeGenerator.Application.DTOs;
 using EnvelopeGenerator.Domain.Entities;
 using EnvelopeGenerator.Infrastructure.Contracts;
-using EnvelopeGenerator.Application.Resources;
+using Microsoft.Extensions.Caching.Memory;
+using DigitalData.Core.DTO;
+using System.Collections.Generic;
+using Microsoft.Extensions.Logging;
 
 namespace EnvelopeGenerator.Application.Services
 {
     public class EnvelopeTypeService : BasicCRUDService<IEnvelopeTypeRepository, EnvelopeTypeDto, EnvelopeType, int>, IEnvelopeTypeService
     {
-        public EnvelopeTypeService(IEnvelopeTypeRepository repository, IMapper mapper)
+        private static readonly Guid CacheKey = Guid.NewGuid();
+
+        private readonly IMemoryCache _cache;
+
+        public EnvelopeTypeService(IEnvelopeTypeRepository repository, IMapper mapper, IMemoryCache cache)
             : base(repository, mapper)
         {
+            _cache = cache;
         }
+
+        public override async Task<DataResult<IEnumerable<EnvelopeTypeDto>>> ReadAllAsync() 
+            => await _cache.GetOrCreateAsync(CacheKey, async entry => await base.ReadAllAsync())
+            ?? Result.Fail<IEnumerable<EnvelopeTypeDto>>().Notice(LogLevel.Error, Flag.NotFound, "No cached envelope types are available in the database. If you have added any envelope types after the server started, please restart the server.");
+        
     }
 }