Add action for end-to-end bima test

[gntouts]

We should add another workflow, where we can test the funcionality of bima.

To do this, we should excute the following steps:

• Use the newly built binaries to create an image using some example unikernel along with example annotations, cmdline and extrafiles
• Push the image to harbor

To take this a step further, we could then pull the image, extract its contents and verify both rootfs's contents and annotations are correct.