[TASK] Use render() as primary ViewHelper method

[s2b]

Until now it was best practice to differentiate between object-based
ViewHelpers, using the object method render() as their primary render
method, and static ViewHelpers, using the static method renderStatic().
This distinction has been introduced to Fluid mainly for performance reasons:
With earlier PHP versions it was quite expensive performance-wise to create a
new ViewHelper object for each ViewHelper call. However, PHP's performance
characteristics for objects have changed quite a bit with newer versions,
which questions the usefulness of this performance optimization nowadays.

Our performance tests have shown that the performance gains are still existent
today if you compare renderStatic() to render() ViewHelpers, especially
if no further optimizations are applied to Fluid's core implementation.
However, the impact is quite small and almost not measurable in real-world
scenarios.

In contrast to that, we see meaningful opportunities for the further development
and optimization for Fluid if we streamline and simplify Fluid's APIs. It
improves the developer experience if there's only one correct way to
implement ViewHelpers and if all ViewHelpers use the same API. For Fluid
internally, this opens up new opportunities of optimization and refactoring,
which are currently not feasible to tackle.

Ultimately, we have taken the decision to deprecate renderStatic() with Fluid v4.
ViewHelpers should use render() as their primary render method from now on.
This patch deprecates both the trait CompileWithRenderStatic and the usage
of renderStatic() without any trait applied to the ViewHelper (which is probably
only an edge case). Instead, the ViewHelperInvoker is called both for uncached
and cached templates to initiate and perform each ViewHelper call.

We will backport the @deprecated annotation on CompileWithRenderStatic to
Fluid v2.15 to let users know in advance of this change.

AbstractConditionViewHelper will be adjusted to this change in a follow-up patch.
There will probably also be further code optimization patches that are made possible
because of this decision, either still in Fluid v4 or later in Fluid v5, when
renderStatic() will be removed completely.