Refactor idea: abstract the Core, making everything else a plugin

[xiaomi7732]

The core of this is a pipe with IFrameLine payloads on it. It runs through PreFilter, Beautifier, Filter and eventually returns. The core shall have an abstraction of the process. Any concreate PreFilter/Beautifier/Filter manipulates the IFrameLine, on different stages, should be plugins.

Blue part for the pipeline, that's the core; Green is the payload; Yellow boxes are various plugins.