[FEATURE] Raise Fluid Standalone to 4.0

This patch raises the minimum Fluid dependency to the just
released Fluid 4. The Fluid team has taken great care to
plan this switch in the Core by introducing a lot of changes
in advance, both with minor releases of Fluid 2 and code
changes in the Core to avoid now deprecated Fluid features.
There are no new deprecations with this release. All
deprecations have already been announced and documented
in previous raises of Fluid 2.x in the Core.

One recently added test case needs to be adjusted with this
change to account for the feature described in the attached
feature RST file.

For a full changelog and more information about the release,
dedicated release notes are available on GitHub:
https://github.com/TYPO3/Fluid/releases/tag/4.0.0

Executed commands:

```
composer req typo3fluid/fluid:^4.0
composer req -d typo3/sysext/adminpanel --no-update typo3fluid/fluid:^4.0
composer req -d typo3/sysext/core --no-update typo3fluid/fluid:^4.0
composer req -d typo3/sysext/f...