sysutils/ddrescueview: Add new port

Small tool that allows the user to graphically examine ddrescue's
mapfiles in a user friendly GUI application.

Features:

• Display ddrescue mapfile in a colored block graphic
• Examine each block in the image with a detailed list of map entries inside
• Zoom inside the mapfile, down to sector level
• To keep track of the rescue process, ddrescueview can automatically re-read the mapfile
• Overlay a domain mapfile, if you use one with ddrescue
• Units can be displayed with decimal (KB, MB...) or binary (KiB, MiB...) prefixes

WIKI: https://sourceforge.net/p/ddrescueview/wiki/Manual-0.4.5/