Deprecation: #89868 - Remove reqCHash functionality for plugins

See forge#89868

Description

Extbase and pi-based plugins that are non-cacheable could previously require the validation of the cHash GET parameter in order to validate GET parameters against the "cHash".

In Extbase plugins, this could be configured via a TypoScript feature toggle (enabled by default):

config.tx_extbase.features.requireCHashArgumentForActionArguments = 1

In Pi-based plugins the public property AbstractPlugin->pi_checkCHash was used to enable the cHash validation for non-cacheable plugins.

Both plugin systems triggered the method TypoScriptFrontendController->reqCHash which validated relevant GET parameters. However, the PageArgumentValidator PSR-15 middleware now always validates the cHash, so a plugin does not need to know about cHash validation anymore and therefore does not need to set the option.

This means the options are not needed anymore, as the validation already happens during the Frontend request handling process. The options are removed.

In addition, the method TypoScriptFrontendController->reqCHash() has been marked as deprecated and is not in use anymore.

Impact

Setting the option in Extbase or Pi-Base has no effect anymore.

Calling the PHP method TypoScriptFrontendController->reqCHash() will trigger a PHP E_USER_DEPRECATED error.

Internal classes such as the CacheHashEnforcer are removed.

Affected Installations

TYPO3 installations with plugins, where one of the options is set, or where the PHP method is called directly.

Migration

Remove the options / flags as they have no effect in TYPO3 v10 anymore.

Calling the method directly is also not needed, as the PageArgumentValidator is executing this validation now at every request.