Optimize saving circuit strategy

[jenalam]

Currently our method of saving circuits doesn't make efficient use of memory. The files we save for each circuit includes:

• The original image
• A screenshot of the circuit after it has been edited (this should overwrite the original image but there's a bug that it doesn't always do that...)
• The OpenCV processed image
• The circuit definition file

We do not have a need to save the OpenCV processed image, as we never use it once the circuit is processed. Furthermore, the only use we have for the original image is to display it as a thumbnail on the home screen under the "Saved Circuits" label. We should compress the original image and shrink it so that it doesn't take up so much space.

[npgoossen]

A downsized image is already saved for the home screen, so it should just be removing the unneeded images

[npgoossen]

So i sort of fixed this while fixing other stuff. Changed to save a downsized image, which is used for processing, and displayed on the home screen (if available, otherwise, displays the circuit schematic drawn in activity)