users: migrations, queries, users crate: create user, get first admin user

crates/database/queries/users/get_initial_admin.sql

@@ -0,0 +1,20 @@
+select u.id,
+       u.created_at  as "created_at: DateTime<Utc>",
+       u.updated_at  as "updated_at: DateTime<Utc>",
+       u.is_admin    as "is_admin: bool",
+       u.username,
+       u.name,
+       u.email,
+       u.password,
+       u.password_recover,
+       u.paper_key,
+       u.is_archived as "is_archived: bool"
+from users u
+
+         inner join settings s on u.id = s.first_admin
+
+where u.is_admin is 1
+  and u.is_archived is 0
+  and u.id is s.first_admin
+
+limit 1

crates/database/queries/users/insert.sql

@@ -0,0 +1,2 @@
+insert into users (id, is_admin, username, password)
+values (?, ?, ?, ?)