Output actual version string rather than a pointer address

[pgporada]

We've seen alerts such as the following where we see Version:0xc0007f8090 which is unhelpful.

checking for early removal: old CRL does not precede new CRL. context: {Old:{Number:+1777047686349361882 NumEntries:227 ThisUpdate:2026-04-24 16:21:26 +0000 UTC NextUpdate:2026-05-03 16:21:25 +0000 UTC URL:http://ye1.c.lencr.org/91.crl StorageKey:{Bucket:le-crl-prod Object:15121864070385704/91.crl Version:0xc000830700}} New:{Number:+1777047686349361882 NumEntries:227 ThisUpdate:2026-04-24 16:21:26 +0000 UTC NextUpdate:2026-05-03 16:21:25 +0000 UTC URL:http://ye1.c.lencr.org/91.crl StorageKey:{Bucket:le-crl-prod Object:15121864070385704/91.crl Version:0xc0007f8090}}}

Adds k.VersionString() method to dereference the pointer into a string.