Introduce rc-zip-sync, rc-zip-tokio (#60)

This PR closes #45: it finally re-introduces an async interface, and it finally introduces a state machine for reading entries.

All the decompressors are now implemented in rc-zip itself, and rc-zip-sync / rc-zip-tokio just plug sync or async I/O into it, as was always the plan.

The sample corpus is tested through sync and async codepaths.

.github/workflows/test.yml

@@ -34,7 +34,7 @@ jobs:
           cargo doc --all-features --no-deps
       - name: Run cargo clippy
         run: |
-          cargo hack clippy --feature-powerset --group-features deflate,deflate64,lzma,bzip2
+          cargo hack clippy --each-feature
       - name: Run tests and collect coverage
         run: just ci-test
       - name: Upload coverage information

.vscode/settings.json

@@ -1,3 +1,13 @@
 {
-	"rust-analyzer.cargo.features": ["default", "lzma", "deflate64", "bzip2", "zstd"]
+	"rust-analyzer.cargo.features": [
+		"rc-zip/corpus",
+		"deflate",
+		"deflate64",
+		"bzip2",
+		"lzma",
+		"zstd",
+	],
+	"rust-analyzer.linkedProjects": [
+		"./Cargo.toml"
+	]
 }