[REQ] Support for Stratus OpenVOS EVF archives

### Is your feature request related to a problem? Please describe
It may be useful, to support extracting Stratus OpenVOS EVF archives, to support data exchange, with systems running this OS. These archives aren't supported by Keka, or any UNIX utiity, at present.

Examples of these files, are available from [Archive.org](https://ia601209.us.archive.org/view_archive.php?archive=/19/items/ftp-ftp_stratus_com/ftp.stratus.com.tar) (the "save.evf.gz" files).

### Describe the solution you'd like
It should be possible to extract files from these archives, to a directory, with a name matching the archive. OpenVOS-style paths (e.g. `*%es#lang3>vos_ftp_site>pub>vos>tools>tcl74`, or `:%es#lang>vos_ftp_site>pub>vos>posix>alpha>posix>build1.out)` should probably be translated to POSIX ones.

### Describe alternatives you've considered
I have tried manually pulling files out of archives, using "strings", "photorec", and "binwalk", although this is not always reliable, as some files have non-obvious structures/headers/boundaries. A C implementation, for OpenVOS, which probably contains enough information, to understand the file format, is available, at https://archive.org/download/ftp-ftp_stratus_com/ftp.stratus.com.tar/ftp.stratus.com%2Fvos%2Futility%2Fevf-2.0.tar.gz.

### Additional context
I am using Keka 1.2.13, on MacOS 12.4, on an ARM64-based system.