Added Sql project with database schema. Added SqlServer repositories for Site, Folder, and User (Cipher still TODO). Switched DI in Startup to SqlServer repos.

src/Sql/dbo/Stored Procedures/User_ReadByEmail.sql

@@ -0,0 +1,11 @@
+CREATE PROCEDURE [dbo].[User_ReadByEmail]
+    @Email NVARCHAR(50)
+AS
+BEGIN
+    SELECT
+        *
+    FROM
+        [dbo].[UserView]
+    WHERE
+        [Email] = @Email
+END