In editor, make "Review issues" link open in a new tab

[johnwatkins0]

Summary

This relates to #5304, but I'm not sure it fixes it.

In the editor, various incarnations of this notice display when there are AMP validation issues at the post's URL:

Previously, this would open in the same tab. Now this will open in a new tab.

Unfortunately, what we are able to do with that link is very limited, so I didn't add the usual icon to visually indicate it would open in a new tab. There is an __unstableHTML parameter we can add to the notice options to allow HTML strings to be passed into the notice, but the inline documentation for notices states very emphatically not to use it.

For similar reasons, we have to use an onClick handler instead of href with a target attribute to open the link in a new tab.

Checklist

• My pull request is addressing an open issue (please create one otherwise).
• My code is tested and passes existing tests.
• My code follows the Engineering Guidelines (updates are often made to the guidelines, check it out periodically).

[johnwatkins0]

I have to look into these test failures, which I don't think are directly related to this change:

1) Test_AMP_Core_Block_Handler::test_register_and_unregister_embed
Failed asserting that '<div class="wp-block-categories-dropdown wp-block-categories"><select name="cat" id="wp-block-categories-2" class="postform">\n
	<option value="-1">Select Category</option>\n
	<option class="level-0" value="1">Uncategorized  (3)</option>\n
</select>\n
</div>' contains "onchange".
/tmp/wordpress/src/wp-content/plugins/amp/tests/php/src/Helpers/AssertContainsCompatibility.php:31
/tmp/wordpress/src/wp-content/plugins/amp/tests/php/test-class-amp-core-block-handler.php:95
2) AmpProject\AmpWP\Tests\ReaderThemeLoaderTest::test_disable_widgets
Failed asserting that an array contains 'widgets'.
/tmp/wordpress/src/wp-content/plugins/amp/tests/php/src/ReaderThemeLoaderTest.php:205

[westonruter]

It may be an issue introduced in the latest Gutenberg. I'll check it out.

[westonruter]

The test failure doesn't happen in Gutenberg v8.8.0. It does happen in v8.9.0. Looking into what changed.

[westonruter]

Using git-bisect identified the failure to be introduced by WordPress/gutenberg@7fbdda2.

[westonruter]

This looks like a bug with Gutenberg. It's exporting the div block container, but not the script that comes after. Going to open a Gutenberg PR to fix.

[github-actions]

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[westonruter]

Going to open a Gutenberg PR to fix.

See WordPress/gutenberg#25026.