Add caching mechanism with CacheService implementation

Introduce a caching mechanism by adding a `CacheService` that implements the `ICacheService` interface. Register the memory cache in `ServiceExtensions.cs` and provide methods for getting, setting, and removing cached items in `CacheService.cs`. Define the caching contract in `ICacheService.cs`.

Author: calin-lupas_dsamcaps

src/DevExcelerateApi/Core/Extensions/ServiceExtensions.cs

@@ -98,6 +98,9 @@ internal static IServiceCollection AddAppServices(this IServiceCollection servic
             services.AddSingleton<ITeamService, TeamService>();
             services.AddSingleton<IIssueService, IssueService>();
 
+            builder.Services.AddMemoryCache();
+            builder.Services.AddSingleton<ICacheService, CacheService>();
+
             return services;
         }
 

src/DevExcelerateApi/Services/CacheService.cs

@@ -0,0 +1,43 @@
+using Microsoft.Extensions.Caching.Memory;
+
+namespace DevExcelerateApi.Services
+{
+    public class CacheService(IMemoryCache memoryCache) : ICacheService
+    {
+        private readonly IMemoryCache _memoryCache = memoryCache;
+
+        public Task<T?> GetAsync<T>(string key)
+        {
+            _memoryCache.TryGetValue(key, out T? value);
+            return Task.FromResult(value);
+        }
+
+        public Task SetAsync<T>(string key, T value, TimeSpan? absoluteExpireTime = null, TimeSpan? slidingExpireTime = null)
+        {
+            var options = new MemoryCacheEntryOptions();
+
+            if (absoluteExpireTime.HasValue)
+            {
+                options.AbsoluteExpirationRelativeToNow = absoluteExpireTime;
+            }
+            else if (slidingExpireTime.HasValue)
+            {
+                options.SlidingExpiration = slidingExpireTime;
+            }
+            else
+            {
+                // Default expiration if none provided
+                options.SlidingExpiration = TimeSpan.FromMinutes(5);
+            }
+
+            _memoryCache.Set(key, value, options);
+            return Task.CompletedTask;
+        }
+
+        public Task RemoveAsync(string key)
+        {
+            _memoryCache.Remove(key);
+            return Task.CompletedTask;
+        }
+    }
+}

src/DevExcelerateApi/Services/ICacheService.cs

@@ -0,0 +1,9 @@
+namespace DevExcelerateApi.Services
+{
+    public interface ICacheService
+    {
+        Task<T?> GetAsync<T>(string key);
+        Task SetAsync<T>(string key, T value, TimeSpan? absoluteExpireTime = null, TimeSpan? slidingExpireTime = null);
+        Task RemoveAsync(string key);
+    }
+}