Magentic One Web Controller

[Merlinvt]

The Web_Controller is part of the Websurfer in the original implementation. I extracted the interaction with the browser into its own class, to separate the concerns somewhat. But mostly just to make the Websurfer agent more mentally graspable.

[AgentGenie]

To merge the PR, we need to close the following gaps.

1. Please add docs to all public APIs and interface/class.
2. Add tests/notebooks to show Websurfer could run properly.