Fix: panic when parsing duration with one digit hours

Change Position Parser

Xmlerrors to anyhow

Attempt to fix #2: Hard parser crashes

- Using the std::sync::Mutex in async is dangerous, switched to tokio's Mutex
- Replaced more .unwrap() with error handling

- Switched implementation of device discovery to use tokio sockets
- Silently ignore parsing errors during device discovery, don't crash
- Changed discover_pnp_locations() signature

Fix #1: parser crashes for devices without serviceList

When the xml is missing the serviceList entirely, the parse_services() method
now returns an empty list.
Also added a unit-test with the crashing xml.

feat: add support for `GetTransportInfo` action

fix: fill empty media url

feat: add support for `Browse` action

feat: subscribe to service events

feat: subscribe to service events

feat: Add support for SetNextAVTransportURI, Next, Previous

remove todo!