Let pwa overwrite "responsive_favicons"'s manifest and theme-color, if both modules are activated

@Grevil: As just discussed, we could alternatively implement that module as dependency or optional dependency instead of our custom upload fields. Please take a look if that makes sense.

If not, we should add a warning on the settings page, if both modules are enabled. Also in the status report.

I'll need to take a deeper look into responsive_favicon to understand it better. At least the on the module page linked favicon generator: https://realfavicongenerator.net/ generates a manifest.json (.webmanifest). We have to see if it is actually used inside the module. If so, we should make a check on each website we have our manifest.json added, to overwrite the favicon manifest.json.

As discussed, we finalized on removing the responsive favicon webmanifest from the html_head entirely and let the user know about this in the status report.

BUT, unfortunately, this isn't simply possible right now, as responsive favicons just puts everything together in the head and doesn't split the different links:

function responsive_favicons_page_attachments(array &$page) {
  $tags = responsive_favicons_load_all_icons();
  if (!empty($tags['found'])) {
    $html = [
      '#tag' => 'meta',
      '#attributes' => [
        'name' => 'favicon-generator',
        'content' => 'Drupal responsive_favicons + realfavicongenerator.net',
      ],
      // This seems like the only way to inject raw HTML into the head section
      // of Drupal 8.
      // @todo find a way to make this better.
      '#prefix' => Markup::create(implode(PHP_EOL, $tags['found']) . PHP_EOL),
      '#suffix' => '',
    ];

    $page['#attached']['html_head'][] = [$html, 'responsive_favicons'];
  }
}

Furthermore, they are no very 'best practice' like put in the 'prefix' of the meta tag.

Let's fix 📌 Split Icon links in their own meta tag definition Needs review first, and then we can properly tackle this issue.

Alright, together with the MR used in 📌 Split Icon links in their own meta tag definition Needs review , this works great! Unfortunately, 'html_head' entries can not be keyed by string, so this complex for each if case is needed. Please review and set to POSTPONED afterward.

@Grevil: Awesome work! Haven't tried this yet, but reviewed the code. Please solve the comments, afterwards we should finally check it works as expected and merge it.

All done, let's wait for 📌 Split Icon links in their own meta tag definition Needs review to resolve and create a follow-up issue for a warning in the meantime as mentioned in https://www.drupal.org/project/responsive_favicons/issues/3382829#commen... 📌 Split Icon links in their own meta tag definition Needs review .

POSTPONED on 📌 Split Icon links in their own meta tag definition Needs review .

Here is the follow-up issue: 📌 Warn about possible conflict with responsive_favicons module Fixed .

Should be minor now we have the warning in place!