BBA/HLE: Code refactoring

[sepalani]

This PR is based on #12533 and #12555. I needed to refactor it to deduplicate parts of the code and to allow some parts to be easier to modify in the future.

It shouldn't have any functional change.

[lioncash]

since these are super basic, it's probably fine to implement these inline.

Also it might be nice to also provide const and non-const begin()/end() member functions so you can iterate without needing to get the iterator off data(), which would be a little more idiomatic.

So rather than:

for (auto& net_ref : m_network_ref.data())

you could just do:

for (auto& net_ref : m_network_ref)

[AdmiralCurtiss]

This can now be rebased, the PRs it's depending on are merged.

[AdmiralCurtiss]

Looks mostly right to me, the one part that isn't obvious to me if it changes behavior or not is 6e2a081, because it swaps the order of the two operations.

[sepalani]

Looks mostly right to me, the one part that isn't obvious to me if it changes behavior or not is 6e2a081, because it swaps the order of the two operations.

The behaviour should be unchanged as the sleeping/enqueued data will be handled later (on the next iteration) after processing the socket data.

[AdmiralCurtiss]

I'll just believe you on that, it seems fine either way.