When viewing traces, it's slightly confusing when the span name doesn't
match the function name. Ensure the names are consistent.
(It might be worth moving most of these to use #[tracing::instrument]
so the name can never go stale. @davidbarsky suggested that is marginally
slower, so I've just done the simple change here.)
This commit also adds `tracing` to NotificationDispatcher/RequestDispatcher,
bumps `rust-analyzer-salsa` to 0.17.0-pre.6, `always-assert` to 0.2, and
removes the homegrown `hprof` implementation in favor of a vendored
tracing-span-tree.
I am not certain if this will improve performance,
but it seems having a .clone() without any need should be removed.
This was done with clippy, and manually reviewed:
```
cargo clippy --fix -- -A clippy::all -D clippy::redundant_clone
```
