[LIBS PLUGINS] Make each and every libs filtercheck result accessible to syscalls plugins

[incertum]

While working on the first iteration of the anomalydetection plugin falcosecurity/plugins#419, it quickly became evident that a significant amount of sophisticated libs code needs to be duplicated. This process is not only tedious but also error-prone, placing additional burdens on developers who simply wish to leverage existing libs capabilities. I see this as complementary to issue #1944, as there will undoubtedly be cases where raw access to state table fields is still necessary.

But in cases where libs code is being copied exactly as-is, it might be worth discussing how we can improve the plugins API to avoid this kind of duplication. What do you think?

[incertum]

/milestone TBD

/assign @jasondellaluce