Adding the ability to paste screenshots into evidence and image preview

[brandonscholet]

I added a preview div above the evidence input.

It will generate an if the uploaded evidence is an image. I achieved this by creating a renderPreview function.

Additionally, added an event listener looking for paste in the window. If that paste had files attached, it will add them to the input and run the renderPreview function.

Documentation-wise, it may be handy to add that images/files can be pasted into the evidence pages.

Also, since submitting the pull request I added the code to have it highlight when a file is dragged over the file input