Target selection design and usability improvements

The target selection option is now available on the toolbar. Previously, the Target selecting toggle was available on the view grid. You can now also enable target selection mode with the keyboard shortcut F7.

While there is no change to how the target selection feature works, the availability of the target selection option on the toolbar and the new keyboard shortcut makes it easy to use the feature. Simply, click the Target selection icon in the toolbar (or press F7) to quickly go into target selection mode and make asymmetric selections or calculations.