compress: Add gzip module & refactor compress & compress.zlib module (#14599)

vlib/compress/gzip/README.md

@@ -0,0 +1,17 @@
+## Description:
+
+`compress.gzip` is a module that assists in the compression and
+decompression of binary data using `gzip` compression
+
+## Examples:
+
+```v
+import compress.gzip
+
+fn main() {
+	uncompressed := 'Hello world!'
+	compressed := gzip.compress(uncompressed.bytes())?
+	decompressed := gzip.decompress(compressed)?
+	assert decompressed == uncompressed.bytes()
+}
+```