Increase Emails Notifications flexibility to allow removing wiki-style rendering icons from notifications

When the wiki-style rendering is active, it includes several functions:

• Displaying image thumbnails.
• Detecting email addresses: emails are shown as a link and a small 'envelope' icon is shown at the end of it.
• Detecting attached files: attached files that are mentioned using the "[^filename]" format, are shown as a link and a small 'green arrow' icon at the end.

Some customers do not require or might be even bothered by the icons shown at the end as attached files in their notifications At the moment it is not possible to just disable a part of the wiki-rendering style, so if a customer wants thumbnails included but not the icons, they have to choose between extra attachments in their notifications (the wiki-style icons are added as attachments) or disabling the wiki-style rendering entirely (worst case scenario is sending text notifications instead of HTML, which defeats the whole purpose).

The suggestion is to allow Email notifications to be configured to NOT include the icons added from the wiki-style rendering or allow configuring the Wiki-style rendering to not include the icons at all.