feature #4: create procedure for citizen

resources/sql/migrations/0000-init_schema.up.sql

@@ -11,19 +11,13 @@ create table "user"
     password   text                                   not null check ( password != '' )
 );
 
-create type "name" as (
-    first_name text,
-    last_name text,
-    civility text
-    );
-
 create table citizen
 (
     id                uuid        default uuid_generate_v4() not null primary key,
     created_at        timestamptz default now()              not null,
-    name              "name"                                 not null check ( name != '' ),
+    name              jsonb                                  not null check ( name ? 'first_name' and name ? 'last_name' ),
     birthday          date                                   not null,
-    user_id           uuid                                   not null references "user" (id),
+    user_id           uuid                                   not null references "user" (id) unique,
     vote_annonymous   boolean     default true               not null,
     follow_annonymous boolean     default true               not null
 );