Bootstrap/Load: Revert the is_*_admin_screen() aliases for is_*_admin() function family.

After some further discussion, it is apparent that the added clarity was subjective, and the `_screen` suffix may not always be appropriate, e.g. in Ajax context. To address any confusion with the existing names, the documentation for these functions can be updated instead.

Additionally, the `is_super_admin_user()` alias for `is_super_admin()` is reverted as well, which may be reconsidered in the future.

Follow-up to [54259].

Props azaozz, jrf, johnbillion, manfcarlo, Clorith.
See #56400.
Built from https://develop.svn.wordpress.org/trunk@54332


git-svn-id: http://core.svn.wordpress.org/trunk@53891 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/capabilities.php

@@ -1084,22 +1084,6 @@ function get_super_admins() {
 	}
 }
 
-/**
- * Determines whether user is a site admin.
- *
- * @since 6.1.0
- *
- * This function is an alias for is_super_admin().
- *
- * @see is_super_admin()
- *
- * @param int|false $user_id Optional. The ID of a user. Defaults to false, to check the current user.
- * @return bool Whether the user is a site admin.
- */
-function is_super_admin_user( $user_id = false ) {
-	return is_super_admin( $user_id );
-}
-
 /**
  * Determines whether user is a site admin.
  *