Send email when the invoice processed

[enescakir]

Improve invoice charging function

We manually charge invoices. I've resolved some issues we encountered during the charging process.

Firstly, I switched the logging method from 'puts' to 'Clog'.

We attempted to charge each payment method listed in the billing information sequentially. Sometimes, the Stripe Ruby SDK throws an error when a payment fails. In such cases, we need to catch the error and proceed to charge the next payment method.

If we successfully charge an invoice, there's no need to continue trying other payment methods, so we break the loop.

If all payment methods fail, we leave the invoice unpaid.

Add cc parameter to the email sending function

We need to cc the support email when sending a failed payment email to the customer. This way, the support team can follow up with the customer if necessary.

Send an email when the invoice is successfully charged

We email the customer once the invoice is successfully processed.

We plan to include the invoice as a PDF attachment in future emails. However, generating a PDF on the backend is complex, so we'll add this feature in the next update.

Send an email when the invoice is failed to charge

We automate the process of sending emails when an invoice fails to charge, including error details from the Stripe API.

We also add the support email as a CC, allowing the entire team to follow up with the customer if needed.

[byucesoy]

Thanks a lot for separate commits. It made reviewing significantly easier.