[FEATURE] Allow the user to set Image size threshold

[duaraghav8]

Allow the user to set soft and hard limits for image size.
This will especially go well with CI integrations - produce warnings if the final image has a size > SOFT LIMIT and fail the pipeline (exit with non-zero) if size > HARD LIMIT

This requires Dockershrink to build the image itself (or at least be able to access metadata of the final image built).

This can be used as a policy in the org to control costs and build & run times.