Make "Include credit limits in balance" setting configurable per account

Currently, the setting “Include credit limits in balance” is a global setting. Some synced accounts may report an overdraft as part of balance and some may not. As a Workarround the credit limit can already be edited and for those account one doesn’t want to apply this setting credit limit can be set to zero as workaround if the bank sync reports one, but it wouldn’t reflect the correct value. Thus, an option to configure it per account is probably useful.