Align some checksum error messages with S3

[cbornet]

Contribution Licensing (no CLA, inbound=outbound, DCO required)

This pull request contributes to PGSTY SILO (pgsty/silo). Code contributions
are accepted under AGPL-3.0-or-later, the same license as the server.
This project does not use a CLA or require a separate Apache-2.0 license grant.
By submitting this pull request I represent that I have the right to contribute
the code changes under this repository's
GNU Affero General Public License v3.0 or later
and retain copyright in my original work. Existing copyright and license
notices remain intact; separately licensed material keeps its applicable terms.
Every commit must carry a DCO Signed-off-by trailer
(git commit -s) certifying the
Developer Certificate of Origin — see
CONTRIBUTING.md.

Description

This aligns some error messages with the error message received on S3

Motivation and Context

Better compatibility with S3

How to test this PR?

• Run tests
• Check that S3 returns these messages

Compatibility impact

Limited: if users rely on the content of the error message in their code.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Optimization (provides speedup with no functional changes)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• All commits are signed off (git commit -s) per the DCO
• Fixes a regression (If yes, please add commit-id or PR # here)
• Unit tests added/updated
• make verifiers passes
• Relevant package tests and make build pass
• Compatibility and rollback impact documented
• Internal documentation updated
• Public documentation update opened in pgsty/silo.pgsty.com, if needed