feat(bson): decrease threshold to when TextDecoder is used to decoder utf8

This increases performance dramatically for anything bigger than 8 bytes.

Old:
 🏎 x 13,430,773.15 ops/sec ±0.53% 0.0000000744558775 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 8 bytes
 🏎 x 8,041,107.43 ops/sec ±0.35% 0.00000012436098 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 16 bytes
 🏎 x 5,014,819.93 ops/sec ±0.35% 0.0000001994089545 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 32 bytes
 🏎 x 2,874,768.67 ops/sec ±1.13% 0.0000003478540759 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 64 bytes
 🏎 x 1,526,007.11 ops/sec ±1.41% 0.0000006553049416 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 128 bytes
 🏎 x 796,015.79 ops/sec ±1.41% 0.0000012562564796 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 256 bytes
 🏎 x 403,319.26 ops/sec ±4.56% 0.0000024794253695 sec/op 	▆▆▇▅▅▅▆▅▆▆▆▆▅▆▆▆▆▆▆▆▅▅▅ decodeUTF8 512 bytes
 🏎 x 6,315,228.55 ops/sec ±0.32% 0.0000001583473967 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 513 bytes
 🏎 x 4,742,931.02 ops/sec ±1.36% 0.0000002108400895 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 1024 bytes

 New:

  🏎 x 14,662,145.39 ops/sec ±0.85% 0.000000068202843 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 8 bytes
  🏎 x 11,979,008.35 ops/sec ±0.71% 0.0000000834793641 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 16 bytes
  🏎 x 11,702,257.92 ops/sec ±1.03% 0.0000000854535942 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 32 bytes
  🏎 x 11,338,091.96 ops/sec ±0.89% 0.0000000881982616 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 64 bytes
  🏎 x 10,793,880.52 ops/sec ±0.62% 0.000000092645087 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 128 bytes
  🏎 x 9,708,723.67 ops/sec ±0.40% 0.0000001030001506 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 256 bytes
  🏎 x 8,184,335.32 ops/sec ±0.59% 0.0000001221846321 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 512 bytes
  🏎 x 8,155,085.35 ops/sec ±0.64% 0.0000001226228736 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 513 bytes
  🏎 x 5,706,045.52 ops/sec ±0.70% 0.0000001752527205 sec/op 	▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ decodeUTF8 1024 bytes

Author: marcj

packages/bson/index.ts

@@ -13,3 +13,4 @@ export * from './src/bson-parser.js';
 export { BaseParser } from './src/bson-parser.js';
 export * from './src/bson-deserializer.js';
 export * from './src/bson-serializer.js';
+export * from './src/strings.js';

packages/bson/src/strings.ts

@@ -13,8 +13,8 @@ import { BSONError } from './model.js';
 const decoder = new TextDecoder('utf-8');
 
 export function decodeUTF8(buffer: Uint8Array, off: number = 0, end: number) {
-    if (end - off > 512) {
-        return decoder.decode(buffer.slice(off, end));
+    if (end - off > 8) {
+        return decoder.decode(buffer.subarray(off, end));
     } else {
         return decodeUTF8Short(buffer, off, end);
     }