Refactor

Some of the methods in MainWindow.xaml were getting too big, with too
high of a cyclomatic complexity.
- Keyboard shortcuts have been moved to a dictionary
- Goto and Find have been given their own methods.
Initial revision of data selection

Time to implement a cursor. As a first pass, highlight data when you're
over the interpretation. This is similar to current functionality.
Found several bugs in the DataRun system while working on this.
bug fixes

- RunStorage: the insertion point calculation for IsWithinDataBlock was
wrong.
- make the selection update whenever the user scrolls/resizes
- Filter pointers that are known to be within datablocks before claiming
the remainder - this removes several false-positives for the pointers.
Since it just checks within and not begins, it shouldn't break pointers
that lead to runs.
Adding mouse control for selection

Allowing single/multiple bytes to be selected and worked with using the
mouse/keyboard as well as the interpretations.