AMADEUS: Implementation of lkt-lib

First implementation of lkt-lib in rust for amadeus and lkt-rs:

• Now amadeus can display basic information
• Also add the base rust parts in lektord

src/rust/liblektor-rs/migrations/2022-09-30-204512_create_posts/down.sql

+DROP TABLE repo;
+DROP TABLE kara_repo;
+DROP TABLE kara;
+DROP TABLE kara_makers;
+DROP TABLE kara_tag;
+DROP TABLE tag;
+DROP TABLE kara_tags;
+DROP TABLE queue_1;
+DROP TABLE history;