Duplicate templates in same namespace is valid use case

Added MR and disabled logging warning "Found multiple files for the", seems it's not wide issue, patch is enough :)

Attached a patch which allows sites to opt out of the warning using their settings.php file:

// Don't attempt to track duplicate templates.
$settings['components_ignore_duplicate_templates'] = TRUE;

Or on the theme/module level:

components:
  # Ignore duplicate templates.
  ignore_duplicate_templates: true

This still requires tests to be implemented, but works for my use case. So feedback is more than welcome on the current implementation.

I had problems applying the diff / patch using cweagans/composer-patches, with a segment being rejected in components.info.yml. This was due to versioning information added by the packaging script on Drupal.org. I manually added the two line change before testing. I don't see this being a problem once the issue has been merged.

I tested with just the patch to make sure that the duplicates are reported by default. As expected, the errors appeared in the watchdog log.

Then I tried again after adding $settings['components_ignore_duplicate_templates'] = TRUE; to my settings.php. After I cleared the cache and refreshed the same page, the errors are no longer logged.

Moving to RTBC.

As a side note, I noticed this bug because I have /web as a symlink to /docroot after changing host providers.