[!!!][TASK] Remove deprecated code related to TSFE

The following code related to TSFE has been removed:

PHP classes:
* TYPO3\CMS\Core\PageTitle\AltPageTitleProvider
* TYPO3\CMS\Frontend\Page\ExternalPageUrlHandler
* TYPO3\CMS\Frontend\Page\PageGenerator
* TYPO3\CMS\Frontend\Page\EidUtility

PHP interfaces:
* TYPO3\CMS\Frontend\Http\UrlHandlerInterface

Methods that have been marked as protected
* tempPageCacheContent()
* realPageCacheContent()
* setPageCacheContent()
* clearPageCacheContent_pidList()
* setSysLastChanged()
* contentStrReplace()

Dropped TSFE methods
* mergingWithGetVars()
* connectToDB()
* initFEuser()
* checkAlternativeIdMethods()
* initializeBackendUser()
* getPageShortcut()
* pageUnavailableAndExit()
* pageNotFoundAndExit()
* checkPageUnavailableHandler()
* pageUnavailableHandler()
* pageNotFoundHandler()
* pageErrorHandler()
* makeCacheHash()
* initTemplate()
* handleDataSubmission()
* initializeRedirectUrlHandlers()
* redirectToExternalUrl()
* checkPageForMountpointRedirect()
* checkPageForShortcutRedirect()
* redirectToCurrentPage()
* processOutput()
* sendCacheHeaders()
* sendHttpHeadersDirectly()
* storeSessionData()
* previewInfo()
* hook_eofe()
* addTempContentHttpHeaders()
* setCSS()
* getUniqueId()
* readLLfile()
* getLLL()
* initLLvars()
* convPOSTCharset()
* convertCharsetRecursivelyToUtf8()
* domainNameMatchesCurrentRequest()
* getDomainDataForPid()
* getDomainNameForPid()

Dropped TSFE properties
* activeUrlHandlers
* page_cache_reg1
* siteScript
* loginUser
* gr_list
* beUserLogin
* workspacePreview
* ADMCMD_preview_BEUSER_uid
* showHiddenPage
* showHiddenRecords
* debug
* MP_defaults
* sys_language_uid
* sys_language_mode
* sys_language_content
* sys_language_contentOL
* altPageTitle
* lang

TSFE Properties now marked as protected
* loginAllowedInBranch
* loginAllowedInBranch_mode
* cacheTimeOutDefault
* cacheContentFlag
* cacheExpires
* isClientCachable
* no_cacheBeforePageGen
* tempContent
* pagesTSconfig
* pageCacheTags
* uniqueCounter
* uniqueString
* pageAccessFailureHistory

TSFE Method Signature changes
* calculateLinkVars now 1st parameter is required
* preparePageContentGeneration now 1st parameter is required
4th Parameter of TSFE->__construct() now unused

Removed TypoScript
* config.typolinkCheckRootline
* config.titleTagFunction
* config.USERUID_substToken
* config.USERNAME_substToken

Hooks
$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['tslib/class.tslib_fe.php']['tslib_fe-PostProc']

Database fields:
* index_phash.data_page_reg1

Resolves: #87235
Releases: master
Change-Id: Id95bb0ccb30852fd115fb9da7754fa2e64374a41
Reviewed-on: https://review.typo3.org/59226


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>