Add resolutions service.

Marechai/Services/ResolutionsService.cs

@@ -0,0 +1,27 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Marechai.Database.Models;
+using Marechai.ViewModels;
+using Microsoft.EntityFrameworkCore;
+
+namespace Marechai.Services
+{
+    public class ResolutionsService
+    {
+        readonly MarechaiContext _context;
+
+        public ResolutionsService(MarechaiContext context) => _context = context;
+
+        public async Task<List<ResolutionViewModel>> GetAsync()
+        {
+            List<ResolutionViewModel> list = await _context.Resolutions.Select(r => new ResolutionViewModel
+            {
+                Id      = r.Id, Width      = r.Width, Height    = r.Height, Colors = r.Colors,
+                Palette = r.Palette, Chars = r.Chars, Grayscale = r.Grayscale
+            }).ToListAsync();
+
+            return list.OrderBy(r => r.ToString()).ToList();
+        }
+    }
+}