Add Praefect rake task to print out replica checksums

What does this MR do?

Related to: #35758 (closed)

When praefect is being used, the administrator needs to be able to know whether or not a given project's repository has the same checksum across its replicas.

it is invoked by:

## by project id
bundle exec rake "gitlab:praefect:replicas[1]"

the output looks like the following:

| project_name | praefect-internal-0 (primary)            | praefect-internal-1                      | praefect-internal-2                      |
-------------------------------------------------------------------------------------------------------------------------------------------------
| test1        | 3f9fe54e92ea1e86bc4af841d8b93dacd788aaeb | 343a4d2e1b1a30dd91e6cc5abebfc7ebc2f0cc93 | 343a4d2e1b1a30dd91e6cc5abebfc7ebc2f0cc93 |
| helllohello  | c5d87c321e349d039d69b8be4d4c4e26cf1b1fd6 | c5d87c321e349d039d69b8be4d4c4e26cf1b1fd6 | c5d87c321e349d039d69b8be4d4c4e26cf1b1fd6 |

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [-] Documentation (if required)
• Code review guidelines
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• [-] Database guides
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• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
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Security

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• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
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