Add some more node:zlib tests

[npaun]

This PR translates the following tests from NodeJS:

• test-zlib-truncated.js
• test-zlib-from-concatenated-gzip.js
• test-zlib-not-string-or-buffer.js
• test-zlib-from-gzip-with-trailing-garbage.js
• test-zlib-from-string.js
• test-zlib-empty-buffer.js

I've removed any existing tests that were redundant with Node's tests. In the process of implementing these tests, I've found two bugs:

• unzip was using the wrong ZlibMode [fixed]
• an issue when streaming multi-member archives [test commented out until this is solved]

I think we don't need any equivalent to this test:

• test-zlib-no-stream.js (https://github.com/nodejs/node/blob/fc02b88f89f8d5abf5ee4414a1026444c18d77b3/test/parallel/test-zlib-no-stream.js#L4)