Add colours to unique ID nodes

Add generic background colours to unique ID nodes
Add changes to launch the diff tool for blocks

Lots of things changed to allow the diff tool to be launched for
different blocks identified by the diff form
Correct start and end indices

Updated the start and end indices to make sure that the blocks being
read were complete and not including the following section
Remove unnecessary tree view

Merging the differences into one tree view list. The one-sided blocks
will be displayed using different background colours and icons