fix(geoip): parse .dat with prost and fix merged network range computation

Replace the hand-written wire parser in load_from_dat_file (geoip.rs and
geoip_converter.rs) with Google's standard protobuf library (prost),
aligned with dae's pkg/geodata. The hand-written parser assumed fixed
field order, single-byte tags and no unknown fields; any .dat variant
silently produced wrong networks.

Fix host-mask computation in the CIDR merge path: !u32::MAX << n is 0,
so merged ranges collapsed to their start address, turning adjacent or
overlapping networks into wrong prefixes. Use u32::MAX.wrapping_shr(prefix)
for the host mask and align the merged start address to the covering
prefix's network boundary before constructing the network.

Author: olicesx

Cargo.lock

@@ -48,6 +48,7 @@ hyper-util = { version = "0.1", features = ["server", "tokio"] }
 http-body-util = "0.1"
 rustls-pemfile = "2"
 base64 = "0.22"
+prost = { version = "0.14.4", features = ["derive"] }
 
 [dev-dependencies]
 criterion = "0.5"