[Filters] [Post Processors] Remove configurable post processor interface for one interface and cleanup filter manager

[robfrawley]

Q	A
Branch?	2.0
Bug fix?	no
New feature?	no
BC breaks?	yes
Deprecations?	yes
Tests pass?	yes
Fixed tickets
License	MIT
Doc PR

This pull request removes ConfigurablePostProcessorInterface and instead adds an optional options array to the normal PostProcessorInterface interface. The new signiture for the post processor process method is:

public function process(BinaryInterface $binary, array $options = []): BinaryInterface;

Additionally, the FilterManager implementation has been cleaned up and reorganized, with (almost) the same functionality. The only change is that now all filters and post-processors are checked for existence before using them, allowing any exception message for missing filters or post-processors shows all the not found items, instead of the first.