refactor: add default to mint memory

crates/cdk/src/cdk_database/mint_memory.rs

@@ -16,7 +16,7 @@ use crate::nuts::{
 };
 
 /// Mint Memory Database
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Default)]
 pub struct MintMemoryDatabase {
     active_keysets: Arc<RwLock<HashMap<CurrencyUnit, Id>>>,
     keysets: Arc<RwLock<HashMap<Id, MintKeySetInfo>>>,

crates/cdk/src/cdk_database/wallet_memory.rs

@@ -18,7 +18,7 @@ use crate::wallet;
 use crate::wallet::types::MintQuote;
 
 /// Wallet in Memory Database
-#[derive(Default, Debug, Clone)]
+#[derive(Debug, Clone, Default)]
 pub struct WalletMemoryDatabase {
     mints: Arc<RwLock<HashMap<MintUrl, Option<MintInfo>>>>,
     mint_keysets: Arc<RwLock<HashMap<MintUrl, HashSet<Id>>>>,