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

Oqtane.Shared/Models/Database.cs

@@ -0,0 +1,9 @@
+namespace Oqtane.Models
+{
+    public class Database
+    {
+        public string Name { get; set; }
+
+        public string Type { get; set; }
+    }
+}