Support VSL version 1 and 64-bit VXIDs

[delthas]

The VSL format was changed, with 3 header lines instead of 2. Namely, VXIDs are now 64-bit integers.

This breaks the library interface (because we change the callback type).

Using the version field, we can still support reading the previous version of the VSL records.

See: https://github.com/varnishcache/varnish-cache/blob/varnish-7.2.1/include/vapi/vsl_int.h See: https://github.com/varnishcache/varnish-cache/blob/varnish-7.3.0/include/vapi/vsl_int.h Fixes: https://github.com/varnishcache-friends/vago/issues/20

[fgsch]

👋 First and foremost, thank you for the PR.

I've been away the last month and I'm just seeing this. Let me have a look in depth and I will get back to you as soon as I can.

[delthas]

Hi, gentle ping 🙂