[BUG] symbols_loaded declared in ebpf events

[NDStrahilevitz]

Prerequisites

• [x] This affects latest released version.
• [x] This affects current development tree (origin/HEAD).
• [ ] There isn't an issue describing the bug.

Select one OR another:

• [x] I'm going to create a PR to solve this (assign to yourself).
• [ ] Someone else should solve this.

Bug description

Technically not a bug just a code redundancy, the symbols_loaded event is defined in the ebpf range both in events.go and tracee.bpf.c, however this is a userspace event, never submitted from the perf buffer. As such it should be removed from the bpf code and it's id declaration moved to userspace.