Use a tracing subscriber for LSP logging (#101)

* Teach `log::` and tracing::` to send `window/logMessage` messages

* Put logging on its own thread

This completely isolates it, and also allows us to maintain all logging related logic in `logging.rs`

* Tweak existing log usage

* Avoid logging during tests

* Fully switch to tracing over log

Right now we don't even have the "compatibility" log layer turned on

* Send an initial log message with the level

* Check `AIR_LOG` envvar on startup

* Tweak expected option name

* Tweak comment

* Do log during testing, but "captured" by default

- `just test` is silent
- `just test-verbose` is noisy and sequential
- CI is noisy and sequential and `trace` level

* Add intermediate `Trace*` structs with custom `Debug` implementations

* Use `Targets` backed filtering

* Always write the request/notify name at `info!()` level

* Use `pretty()` after all because it is useful with spans

* Write out `AIR_CRATE_NAMES` at build time

.github/workflows/test-linux.yml

@@ -51,4 +51,8 @@ jobs:
         run: cargo build
 
       - name: Run unit tests
-        run: cargo test
+        env:
+          AIR_LOG_LEVEL: trace
+        # `--nocapture` to see our own `tracing` logs
+        # `--test-threads 1` to ensure `tracing` logs aren't interleaved
+        run: cargo test -- --nocapture --test-threads 1

.github/workflows/test-mac.yml

@@ -29,4 +29,8 @@ jobs:
         run: cargo build
 
       - name: Run unit tests
-        run: cargo test
+        env:
+          AIR_LOG_LEVEL: trace
+        # `--nocapture` to see our own `tracing` logs
+        # `--test-threads 1` to ensure `tracing` logs aren't interleaved
+        run: cargo test -- --nocapture --test-threads 1

.github/workflows/test-windows.yml

@@ -29,4 +29,8 @@ jobs:
         run: cargo build
 
       - name: Run unit tests
-        run: cargo test
+        env:
+          AIR_LOG_LEVEL: trace
+        # `--nocapture` to see our own `tracing` logs
+        # `--test-threads 1` to ensure `tracing` logs aren't interleaved
+        run: cargo test -- --nocapture --test-threads 1