Add internal rendering pass API

The goal of this task is to evaluate possible solution for an internal pass API and how that would look. Up until now render passes have been hardcoded in a fixed matter, which means adding new passes or extending/changing the existing once have been an involved process.

Being able to more easily add or change how the rendering passes are done means it's more feasible to look at alternative rendering approaches.

The pass API should also support requesting objects of a certain types etc. to facilitate e.g., object tagging.

Once we have a good solution for this, internally, we can start looking at how we expose some of this to the user.

While user APIs are not covered by this task, the end goal is that this will be the enabler for allowing users to enable/disable/replace built-in passes in addition to inserting custom passes before or after the main color pass. Note that this does not open for doing a complete custom rendering pipeline on the user side (we might want to experiment with that internally though, but that's outside the scope of this task).

The work for this has already started with the encapsulation of the render passes, which can be found here: https://codereview.qt-project.org/c/qt/qtquick3d/+/431384