Using script tag helper functions allows plugins to employ the `wp_script_attributes` and `wp_inline_script_attributes` filters to inject the `nonce` attribute to apply Content Security Policy (e.g. Strict CSP). Use of helper functions also simplifies logic in `WP_Scripts`.
* Update `wp_get_inline_script_tag()` to wrap inline script in CDATA blocks for XHTML-compatibility when not using HTML5.
* Ensure the `type` attribute is printed first in `wp_get_inline_script_tag()` for back-compat.
* Wrap existing `<script>` tags in output buffering to retain IDE supports.
* In `wp_get_inline_script_tag()`, append the newline to `$javascript` before it is passed into the `wp_inline_script_attributes` filter so that the CSP hash can be computed properly.
* In `the_block_template_skip_link()`, opt to enqueue the inline script rather than print it.
* Add `ext-php` to `composer.json` under `suggest` as previously it was an undeclared dependency for running PHPUnit tests.
* Update tests to rely on `DOMDocument` to compare script markup, normalizing unsemantic differences.
Props westonruter, spacedmonkey, flixos90, 10upsimon, dmsnell, mukesh27, joemcgill, swissspidy, azaozz.
Fixes#58664.
See #39941.
Built from https://develop.svn.wordpress.org/trunk@56687
git-svn-id: http://core.svn.wordpress.org/trunk@56199 1a063a9b-81f0-0310-95a4-ce76da25c4cd
