set up user settings data table and access repository

src/App/Repositories/Repository.cs

@@ -39,6 +39,11 @@ namespace Bit.App.Repositories
             Connection.Update(obj);
             return Task.FromResult(0);
         }
+        public virtual Task UpsertAsync(T obj)
+        {
+            Connection.InsertOrReplace(obj);
+            return Task.FromResult(0);
+        }
 
         public virtual async Task DeleteAsync(T obj)
         {

src/App/Repositories/SettingsRepository.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Bit.App.Abstractions;
+using Bit.App.Models.Data;
+using Newtonsoft.Json;
+
+namespace Bit.App.Repositories
+{
+    public class SettingsRepository : Repository<SettingsData, string>, ISettingsRepository
+    {
+        public SettingsRepository(ISqlService sqlService)
+            : base(sqlService)
+        { }
+
+        public Task<IEnumerable<IEnumerable<string>>> GetEquivablentDomains(string userId)
+        {
+            var equivalentDomainsJson = Connection.Table<SettingsData>().Where(f => f.Id == userId)
+                .Select(f => f.EquivalentDomains).FirstOrDefault();
+
+            if(string.IsNullOrWhiteSpace(equivalentDomainsJson))
+            {
+                return Task.FromResult<IEnumerable<IEnumerable<string>>>(null);
+            }
+
+            var equivalentDomains = JsonConvert.DeserializeObject<IEnumerable<IEnumerable<string>>>(equivalentDomainsJson);
+            return Task.FromResult(equivalentDomains);
+        }
+    }
+}