Allow user/module to disable theme_debug for particular templates or modules

Description of the need

I'm developing a site, both functionally and with appearance that makes some of its data available as a CSV using views_data_export. I often have theme_debug switched on which then breaks the CSV. This is less an issue for production but it can be a pain in development if the service using the CSV then breaks.

Proposed solution

(A) An optional boolean override for the theme function in core/includes/theme.inc that is then checked here: https://github.com/backdrop/backdrop/blob/6e7b4cc0fabf6040def143c38b88b4...

(B) A documented way for developers to list all templates or calling modules that should be excluded from theme_debug. The theme.inc will then test that in addition to checking the theme_debug setting

Alternatives that have been considered

Describe alternatives you've considered. Have you seen this work in a better way in another CMS?

I created a small hack of theme.inc to test if this principle could work

    if ($theme_debug && strpos($info['template'],'views-data-export')>0) {
      $output = _theme_render_template_debug($render_function, $template_file, $variables, $extension);
    }

This worked but hacking core files is not going to be a sustainable solution and I can't see that this is possible to override in a hook.

The alternative is to switch theme_debug on and off all the time either using Devel or settings.php/settings.local.php Possibly modules could switch the setting off and on again but that may cause other issues

Is there a Drupal or Backdrop contributed module that accomplishes this? ...if so, then please provide a link.

Additional information

Add any other information or screenshots that would help.

Draft of feature description for Press Release (1 paragraph at most)

Backdrop now includes the ability for developers to disable theme_debug for particular modules or templates, for example, if using Views Data Export.