Rename and clear bad code

src/data_provider/card_stats.rs

@@ -1,8 +1,8 @@
-use crate::lang::{CardSetSettings, CardStatistics};
+use crate::lang::{DeckSettings, CardStatistics};
 use rusqlite::Connection;
 use std::time::Instant;
 
-pub fn load_stats_of_set(set: &CardSetSettings, connection: &Connection) -> Vec<CardStatistics> {
+pub fn load_stats_of_set(set: &DeckSettings, connection: &Connection) -> Vec<CardStatistics> {
     let mut stmt = connection
         .prepare("SELECT id, word_id, score, last_opened FROM card_stats WHERE set_id = ?1")
         .unwrap();