Active corrections comment

[Aubrey]

@pierre5018

In addition to the off-on slider, it should be possible to temporarily toggle a setting as long as a control is pressed.

This has two benefits:

• quick compare of the before-after images
• avoids removal of the tool from the palette of “active tools”

This would become unwieldy if one wants to test disabling a parameter correction and change another.

Simply not removing a “switched off” parameter in an “active correction” session would be better.