email from name with comma breaks activity send

related to #7053

if an email from name has a comma and is already in an RFC-compatible format, we deconstruct and reconstruct the name + email. but the deconstruction leaves a trailing '>' which then breaks the address parsing check.

to reproduce, alter your logged in contact to: "John Doe, Jr." (make sure the display name settings include the suffix) and send an activity email. you will receive notice that the from name is invalid.

see attached patch