Update ZipRepository.php to support password protected zip generation

[XPOL555]

#16 added public accessible methods setEncryptionName and setEncryptionIndex on ZipRepository.php

note: idk if we should change also the RepositoryInterface... :/

[theimerj]

Hello, I will look into that shortly. Also I have to fix PHP8 support for the whole thing. Will let you know.