add debug visualizers

[programmerjake]

I'm using hashbrown, but unlike the std wrapper types, lldb doesn't have support for hashbrown's HashMap/HashSet, which makes it very difficult to see what values are stored through the debugger.

[clarfonthey]

Would much rather adopt the existing debug visualisers in the standard library than have ChatGPT plagarise it for us, personally.

Was actually going to propose this as a serious option: since the standard library visualisers already account for hashbrown's layout, we should really leverage those instead of making custom ones, either by moving them into this repo or adopting them to work for both the original and the wrapped types.

[jmigual]

Fair enough. I've deleted my message. I just posted it since this issue has been open for 6 months without any progress.

[clarfonthey]

Progress is slow mostly because we depend on the effort of volunteers. Although to be fair, your comment did, even though it was out of spite, encourage me to think more about the problem and want to actually solve it sooner.

I guess that spite-driven development really is the best.