Add CC, BCC and Attachment field to all emails

[MartinPaulEve]

It would be helpful to allow arbitrary CCs on all emails for those who want them.

• [ ] All email views have a CC input

• [ ] All email views have a BCC input

• [ ] All email views have an attachment input

[severett89]

It would also be helpful and appreciated if BCC can also be added to email fields in Janeway, if possible.

[mauromsl]

see https://github.com/BirkbeckCTP/janeway/issues/1294 while doing this

[joemull]

Originally requested May 5, 2020: https://github.com/BirkbeckCTP/janeway/issues/1542

Mauro's note about a potential implementation: 'I believe we could use the tagging library used for keywords with a custom email validator to present the user a single input element.'