Added IDatabase interface and refactored to use it to handle database type - updated Installer to dynamically add databases to selector

Oqtane.Server/Databases/LocalDbDatabase.cs

@@ -0,0 +1,16 @@
+using Microsoft.EntityFrameworkCore;
+using Oqtane.Interfaces;
+
+namespace Oqtane.Repository.Databases
+{
+    public class LocalDbDatabase : IDatabase
+    {
+        public string FriendlyName => "Local Database";
+        public string Name => "LocalDB";
+
+        public DbContextOptionsBuilder UseDatabase(DbContextOptionsBuilder optionsBuilder, string connectionString)
+        {
+            return optionsBuilder.UseSqlServer(connectionString);
+        }
+    }
+}