rework node:zlib to match internal js api and properly support async writes

.vscode/settings.json

@@ -52,12 +52,15 @@
   "cmake.configureOnOpen": false,
   "C_Cpp.errorSquiggles": "enabled",
   "[cpp]": {
+    "editor.tabSize": 4,
     "editor.defaultFormatter": "xaver.clang-format",
   },
   "[c]": {
+    "editor.tabSize": 4,
     "editor.defaultFormatter": "xaver.clang-format",
   },
   "[h]": {
+    "editor.tabSize": 4,
     "editor.defaultFormatter": "xaver.clang-format",
   },
   "clangd.arguments": ["-header-insertion=never"],

src/brotli.zig

@@ -9,7 +9,7 @@ const BrotliEncoder = c.BrotliEncoder;
 
 const mimalloc = bun.Mimalloc;
 
-const BrotliAllocator = struct {
+pub const BrotliAllocator = struct {
     pub fn alloc(_: ?*anyopaque, len: usize) callconv(.C) *anyopaque {
         if (bun.heap_breakdown.enabled) {
             const zone = bun.heap_breakdown.getZone("brotli");