Add alternative attachments display options to the customer portal configuration

Problem Definition

Currently with the new customer portal attachments are displayed in small square thumbnails even for non-image attachments such as .xls or .pdf documents.
This can prevent reading of the filename and the ability to correctly identify an attachment if many have been added to a ticket.

Suggested Solution

Add a portal configuration option in Jira Service Desk to have attachments display as text-based links using the full filename of the attachment.