Creates the compressed gzip archive.
async gzip.compress(): Promise<void>
Invoking Compress creates the archive specified by ArchiveFile. When the method is called, the file specified by FileDecompressedName will be opened, and the file specified by ArchiveFile will contain the compressed output.
The filename to be stored within the archive is given by FileCompressedName. If this property is set to the empty string, it will be set to an appropriate value automatically; the class always writes a filename in the gzip headers.
As the data is compressed the Progress event will be fired at regular intervals. This event may be used to stream out the gzip file, or to display a progress bar to the user.