Database basic CRUD (#27)

* started schema

* db schemas beginning

* first db schema gen

* added sqlc generation with go generate and sqlite driver

* i think these dependencies are needed

* added IF NOT EXISTS to create and CRUD for each table

* fixed missing columns

* added missing field

* fixed code generation with sqlc

backend/database/sql/schemas/artist_credit_artist.sql

@@ -0,0 +1,7 @@
+CREATE TABLE IF NOT EXISTS artist_credit_artist (
+  id   int PRIMARY KEY,
+  artist_id int NOT NULL,
+  credit_id int NOT NULL,
+  FOREIGN KEY(artist_id) REFERENCES artists(id),
+  FOREIGN KEY(credit_id) REFERENCES artist_credit(id)
+);