Unify process discovery & instrumentation pipeline. And deduplicate Beyla K8s decoration

[mariomac]

Initially, Beyla application instrumentation was split into two pipelines (process discovery & process tracing), as we were planning to split the privileged and unprivileged parts into separate executables.

Since full Beyla can now work without admin privileges, we could simplify the code by joining again the two pipelines.

On one side, that would simplify the code.

On the other side, could slightly improve the speed and memory, as there are some duplicate resources that now could be shared, like the K8s metadata decoration nodes.