add baseline tests for _ and @ in username

However, these don't show any differences as we already parsed these
correctly, while the recent changes have been about serialization.

Author: Byron

gix-url/tests/fixtures/make_baseline.sh

@@ -15,7 +15,7 @@ tests_windows=()
 for path in "repo" "re:po" "re/po"; do
   # normal urls
   for protocol in "ssh+git" "git+ssh" "git" "ssh"; do
-    for host in "host" "user@host" "user@[::1]" "user@::1"; do
+    for host in "host" "user@host" "user_name@host" "user@[::1]" "user@::1"; do
       for port_separator in "" ":"; do
         tests+=("$protocol://$host$port_separator/$path")
 
@@ -42,7 +42,7 @@ for path in "repo" "re:po" "re/po"; do
     tests+=("./$protocol:$host/~$path")
   done
   # SCP like urls
-  for host in "host" "[::1]"; do
+  for host in "user@name@host" "user_name@host" "host" "[::1]"; do
     tests+=("$host:$path")
     tests+=("$host:/~$path")
   done

gix-url/tests/url/baseline.rs

@@ -84,7 +84,7 @@ fn run() {
     }
 
     assert!(
-        failure_count_reserialization <= 42,
+        failure_count_reserialization <= 63,
         "the number of reserialization errors should ideally get better, not worse - if this panic is not due to regressions but to new passing test cases, you can set this check to {failure_count_reserialization}"
     );
     assert_eq!(failure_count_roundtrips, 0, "there should be no roundtrip errors");
@@ -185,8 +185,8 @@ mod baseline {
 
         pub fn max_num_failures(&self) -> usize {
             match self {
-                Kind::Unix => 165,
-                Kind::Windows => 171,
+                Kind::Unix => 198,
+                Kind::Windows => 198 + 6,
             }
         }