Refactor queries: avoid type casts

[ScriptRaccoon]

This is a small refactoring of the queries in the application and the scripts.

• allow passing no values, defaults to empty array
• use built-in generic for db.prepare (from better-sqlite3) to avoid type casts (or rather: let the package do the type cast, there is no runtime check)
• use uppercase AS for all aliases in SQL queries to distinguish them easily (in global searches) from type casts in TypeScript.

So instead of

const categories = db.prepare(`SELECT id FROM categories WHERE ...`).all() as Category[]

we can write

const categories = db.prepare<never[], Category>(`SELECT id FROM categories WHERE ...`).all()

Here, the first generic allows type checking of the passed arguments to .all() resp. .get(). When no arguments should be passed, never[] is appropriate.