Introduce own Numeric type and revert to stdlib from pgx

postgres/queries/accounts.sql

@@ -5,7 +5,13 @@ VALUES ($1, $2)
 RETURNING *;
 
 -- name: GetAccounts :many
-SELECT accounts.id, accounts.name, SUM(transactions.amount) as balance FROM accounts
+SELECT accounts.* FROM accounts
+WHERE accounts.budget_id = $1;
+
+-- name: GetAccountsWithBalance :many
+SELECT accounts.id, accounts.name, SUM(transactions.amount)::decimal(12,2) as balance
+FROM accounts
+LEFT JOIN transactions ON transactions.account_id = accounts.id
 WHERE accounts.budget_id = $1
 AND transactions.date < NOW()
 GROUP BY accounts.id, accounts.name;