Unhandled rejections for default actions using `electron-dl`

[achou11]

Not the end of the world but does add unnecessary noise for those who may have error reporting integrations set up (such as Sentry).

Initial thought is that there should be catches for these calls that just no-op depending on the error (e.g. CancelError), since there's no way to hook into the error-handling when using the default actions.

The relevant actions:

saveImage:

electron-context-menu/index.js

Line 133 in b5d4773

download(win, properties.srcURL);

saveImageAs:

electron-context-menu/index.js

Line 142 in b5d4773

download(win, properties.srcURL, {saveAs: true});

saveVideo:

electron-context-menu/index.js

Line 151 in b5d4773

download(win, properties.srcURL);

saveVideoAs:

electron-context-menu/index.js

Line 160 in b5d4773

download(win, properties.srcURL, {saveAs: true});