feat: TryFrom<&OsStr> to allow direct usage of Url in clap. (#450)

In `clap_derive`, this needs
`parse(try_from_os_str = std::convert::TryFrom::try_from)`.

git-url/src/lib.rs

@@ -210,6 +210,17 @@ impl TryFrom<PathBuf> for Url {
     }
 }
 
+impl TryFrom<&std::ffi::OsStr> for Url {
+    type Error = parse::Error;
+
+    fn try_from(value: &std::ffi::OsStr) -> Result<Self, Self::Error> {
+        use std::convert::TryInto;
+        git_path::os_str_into_bstr(value)
+            .expect("no illformed UTF-8 on Windows")
+            .try_into()
+    }
+}
+
 impl TryFrom<&BStr> for Url {
     type Error = parse::Error;