refactoring: move sql files

resources/sql/functions/user/insert_user.sql

@@ -0,0 +1,18 @@
+create or replace procedure insert_user(inout resource json) language plpgsql as
+$$
+declare
+    new_id uuid;
+begin
+    insert into "user" (username, password, blocked_at)
+    select
+        username,
+        crypt(resource->>'plain_password', gen_salt('bf', 8)),
+        case when blocked_at is not null then now() else null end
+    from json_populate_record(null::"user", resource)
+    returning id into new_id;
+
+    select find_user_by_id(new_id) into resource;
+end;
+$$;
+
+-- drop procedure if exists insert_user(inout json);