Deprecation: #61513 - Use native htmlspecialchars in ExtendedTemplateService 

See forge#61513

Description 

In previous versions the ExtendedTemplateService used a conditional wrapper method to apply htmlspecialchars() for rendering TypoScript search labels, keys and comments in the backend. This option was never used, so htmlspecialchars() was always activated rendering the option and method redundant and not necessary. Calls to the method are removed. The ExtendedTemplateServer method and property are now marked as deprecated for removal with CMS 8.

Impact 

Custom extensions using the flag ExtendedTemplateService->ext_noSpecialCharsOnLabels or a custom implementation of ExtendedTemplateService might get different results when using this switch within the class.

Affected installations 

Installations using ExtendedTemplateService in their own extensions.