Add URL handlers, pyserial feature parity, and cp2110 extra

- open_serial_port now accepts URL schemes (socket://, rfc2217://,
  loop://, spy://, cp2110://) via serial_for_url()
- cp2110 HID-to-UART support gated behind optional [cp2110] extra
- Add grep parameter to list_serial_ports for regex filtering
- Add read_serial_lines for batch multi-line reads
- Add cancel_read/cancel_write for pending I/O interruption
- Add set_flow_control for manual XON/XOFF gating
- Add break_condition to get_modem_lines response

pyproject.toml

@@ -24,6 +24,9 @@ dependencies = [
 ]
 
 [project.optional-dependencies]
+cp2110 = [
+    "hidapi>=0.14.0",
+]
 dev = [
     "ruff>=0.9.0",
     "pytest>=8.0.0",