Replace \Drupal calls with proper IoC in form elements

The Needs Review Queue Bot → tested this issue. It fails the Drupal core commit checks. Therefore, this issue status is now "Needs work".

This does not mean that the patch necessarily needs to be re-rolled or the MR rebased. Read the Issue Summary, the issue tags and the latest discussion here to determine what needs to be done.

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Well, from the test results, you can see why the AccessManager isn't currently injected. That is because it is used inside of public static function processAutocomplete(). You can't access instance variables using $this inside a static function, because there is no instance of the class.

Additionally, there are a lot of WRONG coding standards changes made in the patch. For example:

-   * #element_validate callback for #pattern form element property.
+   * Element_validate callback for #pattern form element property.

This change is wrong because, like the original comment says, the method is the callback used in #element_validate. While it could be worded differently so that #element_validate doesn't appear at the beginning of the comment, changing that to Element_validate destroys the meaning of the comment. The purpose of coding standards changes should be to improve the content, and they should NOT be done just to make a warning go away.

Regardless, coding standards fixes are out-of-scope for this issue and shouldn't be mixed in with unrelated changes.

I think this should be a "Colsed (works as designed)" because the static \Drupal call is the correct way to access a service inside a static function.