Issue #3517493 by dydave: Fixed PHPCS validation errors.

https://www.drupal.org/project/structure_sync/issues/3517493

Fixed all PHPCS validation errors reported by job on Gitlab CI, mostly:

Automated fixes: This MR is the result of the local execution of the following command:

$ phpcbf web/modules/contrib/structure_sync/

PHPCBF RESULT SUMMARY
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FILE                                                                                         FIXED  REMAINING
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/var/www/html/web/modules/contrib/structure_sync/src/Controller/MenuLinksController.php      3      0
/var/www/html/web/modules/contrib/structure_sync/src/Controller/BlocksController.php         3      0
/var/www/html/web/modules/contrib/structure_sync/src/Controller/TaxonomiesController.php     3      0
/var/www/html/web/modules/contrib/structure_sync/src/StructureSyncHelper.php                 18     0
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A TOTAL OF 27 ERRORS WERE FIXED IN 4 FILES
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Time: 1.64 secs; Memory: 14MB