DomPlugin: Add outerHTML for PHP 8.5

Various missing tests, coverage stuff

MethodValue rewrite

This allows us to squeeze a lot more perf out of complex systems
by omitting the access paths and depth. Effectively we can avoid
cloning all methods for every instance and just reuse the existing
MethodValues repeatedly.

Totally incompatible with text renderers since they pretty much
require depth to be set correctly

Utils: Reorder methods

Psalm find dead code

Kint: Pslam type hint for plugin_pool

TextRenderer: Whitelist DateTimePlugin

ClassStaticsPlugin: Fix const cache perf regression

Bugfix adding to folder for first time

ToString: Ignore SplFileInfo too

Just results in repeated SplFileInfoRepresentation dumps