Feature/export

[lucbpz]

What does this PR do?

• Adds the new export dialog to export a volume into a file, a local image and a new image.

[github-actions]

Docker image tag(s) pushed:

felipecruz/vackup-docker-extension:pr-34

Labels added to images:

org.opencontainers.image.title=vackup-docker-extension
org.opencontainers.image.description=Docker Extension to backup and restore docker volumes.
org.opencontainers.image.url=https://github.com/felipecruz91/vackup-docker-extension
org.opencontainers.image.source=https://github.com/felipecruz91/vackup-docker-extension
org.opencontainers.image.version=pr-34
org.opencontainers.image.created=2022-08-08T08:14:22.873Z
org.opencontainers.image.revision=5cffd855e8713e39218ab3eba1bba1e370a70b19
org.opencontainers.image.licenses=MIT

[felipecruz91]

Previously, when saving an image, we had a nice message explaining to users how they could check that the content had been saved successfully in the image.

I think it'd be good to keep it when saving a volume into both a local and a new image, WDYT?