[LIBS PLUGINS] Expose some core libs functionality to the syscalls plugin API

[incertum]

This issue complements existing issues:

• https://github.com/falcosecurity/libs/issues/1711
• https://github.com/falcosecurity/libs/issues/1944
• https://github.com/falcosecurity/libs/issues/2007

For instance, in https://github.com/falcosecurity/libs/issues/1711, there was a request to expose the event enum. Below are some additional functionalities that plugin developers could benefit from, as otherwise, it would require recreating tedious and error-prone libs code:

• Converting back and forth between syscall names and syscall codes and/or event codes
• Some util functions, e.g. concatenating paths in a performant way
• ...

As we discuss the other issues and consider a redesign of the general plugin API and SDK layout, I’ll provide more details here later. Stay tuned.

[incertum]

/milestone TBD

/assign @jasondellaluce