[feat] add initial database schema with tables, triggers, and views

database/main/culture_profession.sql

@@ -0,0 +1,14 @@
+create table culture_profession
+(
+    culture_id    INTEGER not null
+        references culture
+            on delete cascade,
+    profession_id INTEGER not null
+        references profession
+            on delete restrict,
+    primary key (culture_id, profession_id)
+);
+
+create index idx_culture_profession_prof
+    on culture_profession (profession_id);
+