Conversion is done using the `save_image_format` function, so a separate
module is not necessary

The `transparentize` argument struct does not need to save the image,
much like the other arguments, this lets me do batch operations on each
image.
These changes have been done to prepare for batch operations and
operation tracking.

This function runs operations on single images, only saving them
immediately after the operation is complete or quitting with an error
when a failure occurs

This function should check individual images and do various operations
on them.
As of now the functionality is very incomplete.

…mat()

I decided to do individual checks instead as it would be easier to track
individual failed images than to group them all at once

Will replace with a better check

This is a bit of an incomplete implementation but the idea is to store
the decoded result of an image in it's respective task element in the
queue.
Once it has been stored we can check if it has failed or not and check
later on.
Then we obtain the paths of the decoded images

At the moment our error handling schemes are not very good and I hope to
improve that, I will attempt to use AnyHow and see how I can integrate
it's functionality into error handling.
Sadly this commit contains many borrow errors and needs to be
re-evaluated.

Slightly