Improve en-/decode error messages

[decryphe]

With this PR the goal was to improve two things:

• Make wrapped codec-specific errors display their contents, making them presentable to an application user.
  • In the application we're writing, we would like to expose this information via an API to make it easier for an API-user to figure out why a given payload gets rejected.
• Harmonize the other error messages a bit, mainly consistent punctuation, capitalization, removing a single newline and some minor grammar.
  • I tried to be pretty unintrusive with the changes to not change the original authors' intentions (and I would have to read up way more on error usage to do a better job).

Looking forward to feedback/ideas and am willing to do further improvements on error messages if that is of value to the project.

Tested with just all, should be good.

[decryphe]

Is there anything else that needs to be done? I see the CI pipeline is failing.

[decryphe]

The checks now passed on my branch as part of the PR source: https://github.com/decryphe/rasn/actions/runs/22103158594

[XAMPPRocky]

Thank you for your PR! I believe you need to rebase onto main and then the CI and conflicts should be resolved and we can merged.

[decryphe]

Yes, that was it. I hadn't seen that you bumped to edition 2024 in the meantime.