Add server option 'QGIS_SERVER_IGNORE_RENDERING_ERRORS'

[mhugent]

This PR introduces the new server option QGIS_SERVER_IGNORE_RENDERING_ERRORS . If false (the default), the server throws an error (usually http 500 with text 'internal server error') if a rendering error is reported. If true, the server returns the rendered map/layout even if rendering errors occured

[github-actions]

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[kannes]

This looks very useful! Could you add logging of the ignored errors so that they are not completely hidden?

[mhugent]

That's a good idea, I'm going to add logging to the PR

[qgis-bot]

@mhugent
This pull request has been tagged as requiring documentation.

A documentation ticket will be opened at https://github.com/qgis/QGIS-Documentation when this PR is merged.

Please update the description (not the comments) with helpful description and screenshot to help the work from documentors.
Also, any commit having [needs-doc] or [Needs Documentation] in will see its message pushed to the issue, so please be as verbose as you can.

Thank you!

[qgis-bot]

@mhugent
A documentation ticket has been opened at qgis/QGIS-Documentation#10239
It is your responsibility to visit this ticket and add as much detail as possible for the documentation team to correctly document this change.
Thank you!