Provide human readable messages for backend messages

[hannaeko]

Purpose

Provide human readable message for backend generated messages.

Context

When a test times out or dies this is how the new result UI would present the error.

Changes

• use UNSPECIFIED test case when no test case has been provided in message.
• convert backend message tags to human readable messages, allowing for message translation.

UI with the changes:

How to test this PR

• Create a test and make it timeout (set timeout to a small value in backend.ini)
• Query for the test results:

  % ./script/zmb --server http://127.0.0.1:5000 get_test_results --test-id 8c8b436b5b890c8c --lang en | jq '.result.results'
  [
    {
      "module": "BACKEND_TEST_AGENT",
      "testcase": "UNSPECIFIED",
      "message": "The test was unabled to finish.\n",
      "level": "CRITICAL"
    }
  ]
  

For reference here is the ouput of this command on develop:

[
  {
    "testcase": null,
    "module": "BACKEND_TEST_AGENT",
    "message": "BACKEND_TEST_AGENT:UNSPECIFIED:UNABLE_TO_FINISH_TEST \n",
    "level": "CRITICAL"
  }
]

[matsduf]

There is no reason to add the new message to the PO files. When you follow the translation process the PO file will be updated with untranslated (empty) entries for new strings to translate. See "./update-po xx.po" step in https://github.com/zonemaster/zonemaster/blob/develop/docs/internal-documentation/maintenance/Instructions-for-translators.md#translation-steps

[matsduf]

Since the pseudo-level will be displayed to the users, I think it is worth considering its name. Is BACKEND_TEST_AGENT a good name for normal users? What is backend for them? Will we use this pseudo-level for other messages?

ZONEMASTER-TEST-AGENT (is hyphen a problem?) or AGENT or TEST-AGENT or TESTAGENT

And the message I suggest "Zonemaster was unable to start or finish the test" or "It was not possible to start or finish the test".

[matsduf]

There is alread the SYSTEM level. Is there any problem to add that message to that level? If not, then we do not have to create a new level.

[tgreenx]

Maybe reuse SYSTEM yes, and so then we can be extra explicit for the message tag (if we want to) since it will not be displayed to users, e.g. "BACKEND_TEST_AGENT_UNABLE_TO_FINISH_TEST". I'm suggesting to be extra explicit because I think SYSTEM messages come from Engine exclusively.

[matsduf]

I think it is fine to have "ugly" tags (there are more of them) since they are usually not shown.

[hannaeko]

While I agree that SYSTEM would be better I don't think I will make that change in this PR as it would imply migrating the database to change the pseudo module of previous messages.

[matsduf]

I think we can live without migrating the database. I only means that those old tests, which probably are few and have short value, will be displayed differently. I think that is a better alternative than living with that strange pseudotag.

[matsduf]

In general, I like the idea in this PR.

[ghost]

fine to me to go with the "UNSPECIFIED" or "SYSTEM" tag here

[matsduf]

fine to me to go with the "UNSPECIFIED" or "SYSTEM" tag here

I guess you mean pseudo module.

[hannaeko]

There is no reason to add the new message to the PO files.

I removed the update of the PO files from the PR.

I think this PR would be better with SYSTEM as psedo-module, but I do not object it as-is. It is an improvement to provlde an understandable message to the users.

[hannaeko]

I think I will merge this PR as-is and open a new issue for a more long term solution.