Make Claro the default admin theme in Standard profile

Opened an MR with a small patch to make it the default in standard profile.

Already signed off on #3066007: Roadmap to stabilize Claro including the recent updates, I don't think for myself there would be more to sign off here. 🤞

Ok with 83 fails asserting various Seven things, this is a bit out of the scope of what I have energy to fix myself. Any takers? Its mostly about fixing up backend tests.

So this is the only remaining fail and seems to be related to vertical tabs:

1) Drupal\Tests\standard\Functional\StandardTest::testStandard
Behat\Mink\Exception\ElementNotFoundException: Form field with id|name|label|value "Audio file" not found.

/var/www/html/vendor/behat/mink/src/WebAssert.php:636
/var/www/html/core/tests/Drupal/Tests/WebAssert.php:1075
/var/www/html/core/profiles/standard/tests/src/Functional/StandardTest.php:247
/var/www/html/vendor/phpunit/phpunit/src/Framework/TestResult.php:726

From here:

      // The source field should be shown before the vertical tabs.
      $test_source_field = $assert_session->fieldExists($media_type->getSource()->getSourceFieldDefinition($media_type)->getLabel(), $form)->getOuterHtml();

This should IMHO be postponed to figure what exactly to do with vertical tabs.

I’m so excited! 🤩

Claro is now stable so we can now do this.

Also discussed with @catch on Slack and he signed off on this.

COMMITTED AND PUSHED TO 10.0.x AND 9.4.x YEEAAAAHHHH!!!

GREAT work everyone!!!! This is SO great!! :D

ACTION SHOT!

🥳 🥳 🥳

Tagging for the release notes too since this is a change for new site installation.

Go team! So happy to see this after all the years making this theme awesome.