Allow an additional email address to be CC'd or BCC'd during back office membership renewal

In both the 'renew' and 'renew by credit card' back-office membership renewal workflows, only "Receipt From" and "Renewal Message" field are available. There is no CC, BCC, or other type of "send to this email address also" sort of field available as is the case with a public facing contribution page.

In the case of a volunteer or other low-level staff person doing data entry of membership renewals, it might be useful if they were shown a field to send a notification to a higher level staff person, particularly if the membership renewal might warrant a personal touch or reach-out from that higher level staff person.

Another solution might be to display a "Send to my email address also" checkbox, so the membership renewal receipt is sent to the From address. This would allow the org to set up an email rule to filter and forward these emails if needed.