Add support for running a set of tests before pushing images

In the past we've encountered issues with the HAL standalone image being unusable. These issues were mostly caused by JS libraries updates.

Currently, the build & push of HAL standalone images is being done via single step. This issue's proposal is to split this step into two and add a GH action hook to execute test-homepage and test-smoke specs in the TS (https://github.com/hal/berg) with the locally built images and then proceed with the push into the Quay repository.