[feature/release]: Automate consistency verification of local Manifest-file's digest values with draft Manifest-file, during pre-release build

[dstadulis]

Is your feature request related to a problem? Please describe.
Developers must manually verify that the digest values generated produced during a local build match the manifest other developers have created. This verification step could be automated by automatically downloading the draft's manifest file and comparing digest values to what's been produced locally.

Describe the solution you'd like
After developer performs docker-release building,
New enhancement:
0) Edge case, If first developer to build release, upload draft manifest file

1. Obtain draft release's manifest file

gh release download $(gh release list | head -1 | awk '{print $5}') -p "manifest*"

2. verify that all local docker-release digests match, current release's draft manifest file.

Describe alternatives you've considered
Maintainers continue to perform the verification manually, consuming more worker-hours