[BUGFIX] Complete PDF generation with URL and allow any CLI arguments to wkhtmltopdf

Previous patches (c264a830ef4061cf7efcb2e450b5116109150669 and
5292c3db4b047c8a2b437c00c57825cfda556f14) were applied incompleteley and
thus did not work as expected. This patch fix the backend part to be
consistent with previously mentioned patches.
[BUGFIX] Respect "content from page" in Page / RenderContent ViewHelper
[TASK] Avoid reading configuration and roofline if page UID is zero
[BUGFIX] Logout crash on 6.0 when TCA not loaded
[TER] 4.7.8
Revert "[BUGFIX] Logout crash on 6.0 when TCA not loaded"

This reverts commit d97a6c62e7e838d5d5fe356d0e4190e9626c29f0.
[TASK] Avoid amount below minimum, Form / Group ViewHelper
[BUGFIX] Use minimum as start in Form / Group / CountSelector ViewHelper

Avoid rendering invalid option values if $minimum is not zero.
[TASK] Move skip condition up as far as possible in content TS registration method
[BUGFIX] GP('L') must not be sys_language_uid (Thanks to Marc Hirdes)
Merge pull request #14 from matthiasnitsch/sys_language_for_menu

FORGE #43660 fed:page.menu don't respect config.sys_language_uid
[FEATURE] Workspace awareness for template fetching
[BUGFIX] Fixed a problem with getFlexFormSource
[TASK] Added function doc comments for new workspace capable functions
[TASK] Display Extended tab also on Fluid Content Elements
[TER] 5.0.0
[BUGFIX] Avoid returning template variables if unable to process page's FlexForm data
[TER] 5.0.1
[TASK] Avoid adding potentially unused default FCE tab
[BUGFIX] Don't shutdown GLOBALS exec time, apparently makes 6.0 crash