Add the Rust-based netflow plugin that receives, decodes, and indexes
NetFlow v5/v9, IPFIX, and sFlow v5 flow data. Includes the Go-based
topology IP intelligence downloader for GeoIP/ASN enrichment, journal
infrastructure improvements, build system integration, and packaging.

Add pcap capture files for NetFlow v5/v9, IPFIX, and sFlow v5 protocol
testing including edge cases for MPLS, NAT, SRV6, VXLAN encapsulation,
multiple sampling rates, and vendor-specific templates.