1. decompressionstream api

2. decompressionstream api: `decompressionstream()` constructor

3. decompressionstream api: `decompressionstream()` constructor: "deflate" compression

4. decompressionstream api: `decompressionstream()` constructor: "deflate-raw" compression

5. decompressionstream api: `decompressionstream()` constructor: "gzip" compression

6. decompressionstream api: readable

7. decompressionstream api: writable