Added functions for adding, deleting and showing tickets

As said, functions got implemented. Also minor changes to migration
layout and dependencies

migrations/20260422094704_types.up.sql

@@ -0,0 +1,2 @@
+CREATE TYPE category AS ENUM('Whiteboard Beamer', 'Internet', 'iPad Koffer', 'Apple TV', 'Docu Cam', 'Sonstiges');
+CREATE TYPE status AS ENUM('ToDo', 'InProgress', 'Done', 'Archived');