Refactoring cap-ci pipeline.

[bikramnehra]

Following major changes are added:

• reading config from a file.
• updating deployment script.

[bikramnehra]

Test pipeline deployed here: https://concourse.suse.dev/teams/main/pipelines/test-cap-release-pipeline

I haven't moved everything to config.yaml, may be we can discuss what else should be moved.

[bikramnehra]

Test pipeline deployed at: https://concourse.suse.dev/teams/main/pipelines/test-cap-release-pipeline

[HartS]

LGTM