Url constructor

Represents a Uniform Resource Locator (URL) and provides methods to parse, construct, and open connections to the referenced resource.

This class acts as a convenient wrapper around Dart's built-in Uri class, and integrates with JetLeaf's networking system to provide typed access and connection management.

Use Url when you need structured access to URL components or want to establish a connection via UrlConnection.

Example: Parse and connect

final url = Url('https://example.com/api/data?user=42');
print(url.host);     // example.com
print(url.query);    // user=42

final stream = await url.openStream();
int byte;
while ((byte = await stream.readByte()) != -1) {
  print(String.fromCharCode(byte));
}
await stream.close();

Parses the given spec string into a Url instance.

Throws a MalformedUrlException if the URL is not valid.