Factor out StatementList to sqlutil and use it in userapi

It helps with the boilerplate.

internal/sqlutil/sql.go

@@ -152,3 +152,19 @@ func RunLimitedVariablesQuery(ctx context.Context, query string, qp QueryProvide
 	}
 	return nil
 }
+
+// StatementList is a list of SQL statements to prepare and a pointer to where to store the resulting prepared statement.
+type StatementList []struct {
+	Statement **sql.Stmt
+	SQL       string
+}
+
+// Prepare the SQL for each statement in the list and assign the result to the prepared statement.
+func (s StatementList) Prepare(db *sql.DB) (err error) {
+	for _, statement := range s {
+		if *statement.Statement, err = db.Prepare(statement.SQL); err != nil {
+			return
+		}
+	}
+	return
+}